Ansys Solutions 05 2006

ANSYS Mechanical performsreal-time analysis for jet engineturbine components based onin-service usage.

The Fiat Panda reached fuelefficiency goals through aero-dynamic studies performedwith ANSYS CFX.

Industry Spotlight

ANSYS 11.0 brings togetherpowerful enhancements tobroaden the role of simulationin product development.

Oil and Gas

For ANSYS, Inc. sales information, call 1.866.267.9724, or visit www.ansys.com.To subscribe to ANSYS Solutions, go to www.ansys.com/subscribe.

ANSYS Solutions is published for ANSYS, Inc. customers, partners and others interested in the field of design and analysis applications.

Editorial DirectorJohn [email protected]

Managing EditorFran [email protected]

DesignersMiller Creative [email protected]

Art DirectorDan [email protected]

Ad Sales ManagerBeth [email protected]

Circulation ManagerElaine [email protected]

www.ansys.com ANSYS Solutions | Volume 7, Issue 5 2006

Neither ANSYS, Inc. nor the editorial director nor Miller Creative Group guarantees or warrants accuracy or completeness of the material contained in this publication. ANSYS,ANSYS Workbench, CFX, AUTODYN, FLUENT and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarksof ANSYS, Inc. or its subsidiaries in the United States or other countries. ICEM CFD is a trademark used under license. All other brand, product, service and feature names or trademarks are the property of their respective owners. POSTMASTER: Send change of address to ANSYS, Inc., Southpointe, 275 Technology Drive, Canonsburg, PA 15317 USA.

©2006 ANSYS, Inc. All rights reserved.

Editorial AdvisorKelly [email protected]

Editorial ContributorsLiz Marshall Chris [email protected] [email protected]

Expanded and IntegratedSolutions in ANSYS 11.0ANSYS 11.0 brings together powerful enhancements to broadenthe role of simulation in productdevelopment.

Latest Tools for ThermalAnalysis of ElectronicsA wide range of ANSYS software is available to study cooling in electronics parts and systems.

ContentsIndustry Spotlight

Features

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Departments

Simulation at WorkDevelopment of an Innovative Snowthrower Steering System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Meeting European Emissions for Trucks. . . . . . . . . . . . . . . . . . . . . . . . 26Meeting Market Requirements for Industrial Pumps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Pressure Loss in Pipes with Sudden Contractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Tech FileGenerating Interpolated Data with Beam and Shell Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Technology UpdateNonlinear Stabilization Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Industry NewsAnnouncements and Upcoming Events . . . . . . . . . . . . . . . . . . . . . . . . . 3

Tips and TechniquesANSYS Workbench Makes Simulating FSI Easier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

EditorialThe Spectacular Value of Being Right . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Simulation-Based Life-CycleCost ManagementANSYS Mechanical performs stressand thermal analysis for calculatingas-flown fatigue life of critical jetengine turbine components.

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CFD Helps Design an Eco-Friendly CarThe Fiat Panda reached fuel efficiency goals through aerodynamicstudies performed with ANSYS CFX.

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The use of simulation plays akey role in enabling betterexploration of new oil and gasfields, transportation of rawmaterials and transformationof this resource into everydayproducts. Read more in this issue’s Industry Spotlightarticle beginning on page 5.

About the cover

Guest CommentaryRunning CAE Activities as a Lean Business. . . . . . . . . . . . . . 40

Oil and GasAdvanced simulation tools helpmeet growing worldwide needsfor oil and gas as a criticalresource for energy and materialsin a wide range of products.

Editorial

The Spectacular Value of Being Right

Save time, lower costs, main-tain quality — these are thebenefits most companies goafter with engineering simula-tion. For decades, that’s beenthe name of the game: crankout products faster, cheaper,better than the competition.Using simulation, companiescan spot and fix problems earlyin the cycle, thereby reducingthe high cost and long delays of going through numerous hardware tests.

These proven benefits certainly are well docu-mented. In one recent study, “The Simulation-DrivenDesign Benchmark Report,” the Aberdeen Group foundthat 100 percent of best-in-class manufacturers —those meeting cost, revenue, quality and launch datetargets 86 percent or more of the time — use simulationin the design phase and average 1.6 fewer prototypesthan all other manufacturers. With the help of simulation, these top performers, on average, were able to get the most complex products to market 158days sooner with $1.9 million lower development costs. Manufacturers with the simplest products shortened launch times by 21 days and saved $21,000in development costs.

Most companies would jump at the chance torack up these impressive numbers. Indeed, when itcomes to time, cost and quality, failing to deliver onany one of these subtracts significantly from the bottom line. The penalty of being wrong is high, andthe benefit of Simulation Driven Product Developmentin avoiding these deficiencies is unquestionable. But that’s only part of the story and, certainly, no guarantee of market success. In fact, a well-designed,inexpensive, quality product launched incredibly fastcan still be a total flop if it’s uninteresting and nobodywants to buy it.

That’s why forward-thinking manufacturers aimfor innovation — continually capturing the imagination

By John KrouseEditorial DirectorANSYS [email protected]

By reducing hardware test cycles, engineering analysis helps avoid bottom-linepenalties of being wrong regarding time, cost and quality on individual projects and product launches. But the greatest benefit of a systematic Simulation DrivenProduct Development approach is the sustainable business value of being rightyear after year with steady streams of design innovations that capture the imagination and dazzle the market.


of the market with a steady stream of top-performingsuccessful products. These companies listen to thevoice of the customer, anticipate swiftly changingtrends and know buyer expectations. Their productsare innovative because they stand out from the crowd,and their development processes are innovativebecause these companies can quickly crank out successful designs one after another, year after year.In a recent study by Momentum Research Group, thenumber-one way for improving competitiveness citedby corporate decision makers was to increase the rateat which their organizations deliver product and service innovations. In another survey by The Boston Consulting Group in conjunction with BusinessWeekmagazine, an overwhelming majority of senior execu-tives named innovation as one of their top priorities.

Unsurprisingly, Simulation Driven Product Devel-opment is at the foundation of many of these efforts inachieving repeatable and efficient design innovation.Instead of rushing to production, smart companieshave learned that time saved by reducing the numberof hardware tests near the end of development can beutilized early in the cycle to drive innovation. By usingengineering analysis tools to evaluate alternativeideas, guide the design and refine concepts in the initial stages of product development, organizationsfront-load the process to cultivate the creativity andinventiveness necessary for true innovation.

Leading-edge companies leveraging SimulationDriven Product Development know that the greatestvalue of the technology is that it enables them to pullahead of competitors with innovative products andprocesses. They don’t just avoid bottom-line penaltiesfor being wrong; they get spectacular business value from being right — adding money to top-line revenue streams, increasing brand recognition andsustaining ongoing profitability growth by hitting the bull’s-eye, time after time, with unique and highlysuccessful products.

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Industry News

Recent Announcements and Upcoming Events

Top-Performing Manufacturers Using Simulation in Design Phase

A recent Aberdeen benchmark study examines whenand how companies use simulation during productdevelopment and correlates this usage with their performance. The study found that 100 percent ofbest-in-class manufacturers reported using simulationin the design phase, while only three out of four of thepoorest performers do the same. The report also discloses best practices in using simulation that lead tosuperior product development performance. AberdeenGroup, Inc. provides fact-based research and insightsfocused on the global, technology-driven value chain.The report was made available to the public throughpartial underwriting by ANSYS, Inc.

Moldflow® Plastics Insight 6.1 Offers New Capabilities

Moldflow Corporation, a leading provider of design-through-manufacturing solutions for the plastics injection molding industry, released the latest version ofits powerful and widely used plastics design analysissoftware. Moldflow Plastics Insight (MPI) 6.1 deliversnew technologies and key enhancements to help usersinvestigate and solve potential design issues, betterinterface with structural CAE software programs,reduce solution time and work more efficiently.

One of the most significant new features in MPI 6.1 isthe ability to predict birefringence (also known as double refraction), a phenomenon that causes opticaldefects in lens applications. This feature will allowdesigners of optical parts to eliminate such defects inapplications ranging from automotive to consumerproducts to medical. For more information, visithttp://www.moldflow.com.

Microsoft and Bull Put High-Performance Computing Within Reach

Microsoft Corporation and Bull SAS, one of Europe’slargest information technology companies, announcedthe availability of Windows Compute Cluster Server2003 on Bull NovaScale® R400 clusters, built fromhigh-performance Intel® Xeon® processor-basedservers. The partnership marries Microsoft’s high-performance computing (HPC) platform with theproven capability of Bull in HPC clusters, creating aneasy-to-use, scalable infrastructure, featuring the bestprice-to-performance ratio.

Windows Compute Cluster Server 2003 is Microsoft’sfirst software offering designed specifically to run parallel, HPC applications for customers solving complex computations. Bull, with deep expertise indesigning and delivering HPC, has complemented itstraditional offerings with Windows CCS 2003 solutionsto address the needs of industrial users who need fastand easy turnkey solutions for their mechanical computer-aided engineering (MCAE) applications. Formore information, visit http://www.bull.com.

Linux Networx Delivers Immediate Productivity forLeading Supercomputing Applications

Linux Networx announced the next member of the LS Series, Performance Tuned (LS-P) Linux Super-systems. The LS-P Series of turnkey, production-ready systems delivers industry-leading applicationthroughput and significant reductions in total cost of ownership for leading product design applications.LS-P systems are performance tuned for computa-tional fluid dynamics (CFD), crash/impact analysis and structural analysis applications. Visualization software from CEI is supported as a tuned, integrated application on all systems.

Linux Networx LS-P Supersystems eliminate the complexity associated with high-performance Linuxclusters. They are delivered as state-of-the-art super-computing systems that are production-ready withindays of delivery. As turnkey systems, the LS-P familyeliminates the expected customer time and expenseassociated with installing, integrating and tuning application software, as well as hardware and systemsoftware integration and tuning. For more information,visit http://linuxnetworx.com.

TyanPSC Reaches 256 Gigflops for PersonalSupercomputing

TyanPSC, a business unit of Tyan Computer Corporation, launched the next generation in personalsupercomputing: the Typhoon 600 series using Intel Xeon 5300 Clovertown processors. LeveragingTyan’s experience of 2.5 million users, TyanPSC hasdesigned a personal supercomputing platform thatcombines the best computational horsepower, thebenefits of a personal or workgroup resource and the streamlined user experience that engineers andscientists expect from a PC. TyanPSC’s next genera-tion Typhoon personal supercomputer is an easy-to-

Industry News

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deploy, easy-to-use turnkey system that delivers astunning 256 GFLOPs in the office or any other environment while requiring only 15 amps from a standard wall outlet. For more information, visithttp://www.tyanpsc.com.

Icepak 4.3 Offers Enhanced Flexibility and Automation

Icepak 4.3 electronics cooling design software intro-duces key new technologies in the thermal design ofelectronic systems. Direct representation of CADgeometries expands the ability of Icepak software tohandle complex geometry with this new capability,providing additional flexibility and a higher degree ofautomation while modeling complex shapes in today’selectronics components and systems. A new meshingtechnology has been introduced into the software forfast and optimal meshing of CAD geometries. Icepak4.3 also introduces direct import of trace and viadetails from MCM/BRD and Gerber files of printed circuit board (PCB) layout along with a new method toaccurately represent these details. For more informa-tion, visit http://www.icepak.com.

Cooperation between Materialise and FluentResults in 3Matic-for-FLUENT

Materialise, the world leader in software develop-ment for rapid prototyping and industrial design applications, announced the first release of 3Matic-for-FLUENT, a custom-developed batch geometry pre-conditioning module that is the outcome of the successful collaboration between Materialise and Fluent Inc. When combined with the Fluent TGrid 4.0wrapper technology, 3Matic-for-FLUENT improves theCFD process of geometry to meshed model for a widerange of applications.

Materialise 3Matic technology provides powerfulgeometry conditioning tools that have been used in rapid prototyping successfully for years. Last year,Materialise and Fluent teamed up to further developthis triangular meshing technology to meet the specificneeds of FLUENT CFD software users. Materialise’specialized Software Development Services team has worked closely together with Fluent on theautomation process. For more information, visithttp://www.fluent.com.

Icewave 1.1 Software Offers ElectromagneticCompatibility and Interference Analysis

Version 1.1 of Icewave electromagnetic compatibilityand interference (EMC/EMI) analysis software incorpo-rates enhanced model building capabilities and radiation computation for EMC/EMI analysis of

electronics systems. A new 64-bit solver allows usersto solve complex systems without being restricted by memory limitations of 32-bit operating systems.Using its enhanced model sharing capabilities withIcepak thermal design software, Icewave 1.1 makes engineering workflows that require thermal and EManalysis easier than ever before. This capability allows system designers of high-performance electronicssystems to dramatically reduce time from concept tomarket by simulating electronic design in a single CAD environment. For more information, visithttp://www.icepak.com.

ANSYS Addresses User Communities with Industry-Specific Conferences

International Aerospace CFD Conference

June 18 – 19, 2007Paris, Francehttp://www.iacc.ansys.com

The first International Aerospace CFD Conference(IACC) has been uniquely designed to bring togetherthe international aerospace/defense computationalfluid dynamics (CFD) user community for ANSYS CFX,ANSYS ICEM CFD and FLUENT products. The confer-ence will offer keynote presentations from industrythought leaders, leading-edge applied CFD papers,best practice sessions for new technologies and aPartner Pavilion.

European Automotive CFD Conference

July 5 – 6, 2007Frankfurt, Germanyhttp://www.eacc.fluent.com/

The biennial European Automotive CFD Conference(EACC) is a one-stop CFD conference for road, rail,racetrack and off-highway vehicle engineering. Thethird EACC offers a unique opportunity for updates onthe latest technologies in computer-aided engineering(CAE) for the automotive industry. The conference willoffer presentations from internationally renownedautomotive companies, leading-edge applied CFDpapers, best practice sessions for new technologiesand a Partner Pavilion.

Oil and natural gas furnish about three-fifths of theworld’s energy needs, fueling our homes, workplaces,schools and factories, and transportation systems. Inaddition, petroleum constitutes the raw materials forplastics, chemicals, medicines, fertilizers, constructionmaterials and synthetic fibers. As a result, the industryhas become a key element in our daily lives and anintegral part of today’s global industrial economy.

Currently, the United States is the world’s largestconsumer of oil and natural gas, using 25 percent ofglobal production. In September 2006 alone, the totalpetroleum products delivered to the U.S. domesticmarket totaled 20.5 million barrels per day. Because ofits critical importance worldwide, global demand for oiland gas is expected to increase by 22 percent in thenext 10 years. Asia and its emerging markets of Chinaand India lead this increase, with these two nationsmore than doubling their consumption since 1990.Moreover, China’s Sinopec Development ResearchInstitute predicts that China’s oil consumption will double during the next 15 years to more than 10 million barrels per day. Capital expenditures in the

Oil and GasAdvanced simulation tools help meet

growing worldwide needs for oil and gasas a critical resource for energy and

materials in a wide range of products.By Robert BayesSales ManagerANSYS, Inc.

World Marketed Energy Use, 1985 – 2025 (Projected)

Source: Energy Information Administration, U.S. Department of Energy

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Industry Spotlight


oil and gas industry also are on the increase. A BoozAllen Hamilton report indicated that of the 20 majorcompanies they surveyed, 80 percent planned to increase capital expenditures over the next fiveyears, including planned increases of 30 percent in2006 alone.

Facing Risk and Uncertainty

Few industries are burdened with more uncertainty —or more risk — than oil and gas. From exploration toproduction to delivery, a wide variety of challenges are being met with engineering simulation.

Drill-bit technology and offshore platforms havebeen improved, permitting faster, more effectivedrilling for longer periods in fields once consideredinaccessible. In the past unthinkable, hydrocarbonreserves below 9,000 feet of seawater or imbedded inshale or sand now can be extracted. Technologicalinnovations have enabled rigs to operate offshore andon land 24 hours a day to drilling depths of more than10,000 feet.

Pipelines more thanthree feet in diameter carry-ing in excess of a million bar-rels of oil daily can withstandextreme conditions, includingarctic and desert temperatures, aswell as crushing and turbulentundersea forces. Giant tankers with ever-greater capacities are designed to withstandhuge compressive and shear forces, making theseversatile carriers not only highly efficient but, above all,safer for crew and the environment. Refinery opera-tions have been improved to more effectively processcrude materials into specific products.

In these areas, the use of simulation plays a keyrole in enabling better exploration of new oil and gasfields, transportation of raw materials and transforma-tion of this valuable resource into products that people, companies and nations around the worlddepend on so heavily. Engineering analysis is indispensable in many of these applications and willundoubtedly prove to be critical as companies in theoil and natural gas industry face ever more demandingchallenges in the decades to come.

Offshore Platforms for Drilling Deeper

Ever since 1887, when the first offshore drilling rig was deployed 300 feet off the Pacific Coast, oil and gas producers have been forced to drill in pro-gressively deeper waters to extract the resources their customers demand. And the deeper they drill, themore complicated the engineering problems. Afterabout 1,300 feet, fixed oil platforms that sit on theocean floor are no longer viable. Engineers solved this problem by creating floating platforms such as semi-submersibles, tension leg platforms (TLPs), spars, andfloating production storage and offloading (FPSO)platforms that are held in place by moorings anchoredto the ocean floor.

All floating platforms must survive in the harshenvirons of the open ocean. Designs must be engi-neered to withstand elements such as waves, oceancurrents, salt water and wind. ANSYS software is usedby many major offshore platform designers — such asJ. Ray McDermott Engineering (JRME) with facilities inthe Americas, Middle East, Caspian and Asia Pacific— for incorporating survivability into their products.

Although initial engineering simulation work in theglobal oil and gas industry was limited to R&D andspecial projects, low-cost compute capability grew the demand for optimization. Worldwide competitionprompted the need to optimize all aspects of platformdesign and produce a more efficient design to reducetotal installed cost. JRME’s usage of ANSYS softwareexploded into everyday use on all designs.

Design of offshore platforms revolves aroundloading, calculation of stress and displacement, and assuring compliance with industry-developed standards. ANSYS Structural tools are used primarilyto calculate stresses and deflections. JRME usesinternal software and other commercially availabletools to develop loadings and complete the necessarypost-processing. They also develop translators toensure streamlined communication between the various software tools to complete a proper design.

Today, ANSYS technology is used on all newJRME designs. For a shallow water platform design,such engineering simulation may amount to only 10percent of the engineering time and cost, but for adeepwater or floating platform it may be more thanhalf the cost. As JRME engineers use the software,they improve productivity and identify additional uses,which further improves the company’s productivityand lowers overall engineering cost.

Studying the Ocean’s Dance

The increasing worldwide demand for natural gasrequires new concepts for gas import. Lightering, the process of offloading and transferring gas fromlarge tankers to smaller ones, is economical andsometimes necessary at ports with narrow entrances,shallow waters or small berths. In addition, some communities mandate lightering so offloading facilitieswon’t destroy the scenic view of the shoreline.

Single Buoy Moorings (SBM), headquartered inthe Netherlands with technical centers in Monaco andHouston, Tex., U.S.A., has developed a floating storage and re-gasification unit (FSRU) to enable

High-performance, low-cost computecapability has made engineering simulation aneveryday and indispensable tool for the oil and gasindustry. JRME uses ANSYS Structural software to mesh hugemodels, such as this offshore spar and barge.

Industry Spotlight

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SBM performed model tests for in-depth verification of hydrodynamics withFSRU (left) and LNGC (right). Note the wave probes between the vessels tocapture the wave elevation in the gap.

LNGC surge motions calibration helps SBM to design saferequipment for natural gas offloading operations and developside-by-side mooring systems.

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The calibration of this numerical model takes intoaccount the accurate description of the basin wavefield and the latest developments concerning the interactions of two vessels in close proximity. SBMuses these results in designing safer equipment foroffloading operations and developing novel side-by-side mooring systems.

Quantifying Safety and Environmental Riskswith SimulationEvery year, more than 120 million metric tons of LNGare shipped, worldwide, between 40 LNG-receivingand re-gasification terminals in the world; about 130ships are currently in operation, 1,000 feet or so inlength and holding the equivalent of 20 billion gallonsof natural gas. With such statistics, the potential for explosion and fires — and risk to life and the environment — is of great concern.

FLUENT CFD software is being used to addressthis challenge by modeling various LNG accident scenarios, bringing a higher level of objectivity to therisk-reward calculations. FLUENT technology has theability to model combustion accurately along with therelated flow of liquids and gases while tracking flowrates, temperature, pressure and species concentra-tion. Using a scenario of a breached tanker and subsequent fire, the FLUENT simulation addresseddifferent phases: the liquid natural gas, surrounding air and seawater; chemical reactions involved in com-bustion, in which methane and air react to form waterand carbon dioxide; and the size of the hole fromwhich LNG escapes. The goal of the simulation was toaccount for the spreading of cryogenic liquid on water,the evaporation process, the dispersion of densegases, ignition, and combustion.

A suitable boundary was defined within which themathematical equations governing fluid flow was calculated. Analysts generated a mesh within theboundary of a sphere that surrounded the ship and

offshore import of liquid natural gas, or LNG. Side-by-side (SBS) mooring systems are developed for non-dedicated LNG carriers (LNGC) using standardmanifolds and mooring equipment on the LNGC.

Model tests were performed at the MaritimeResearch Institute Netherlands (MARIN) for in-depthverification and calibration of the hydrodynamics oftwo SBS vessels. The vessels were tested in 60mwater depth against a large range of design wave systems for offloading operations.

The objective of the calibration was to accuratelyreproduce the measured vessels’ motions in irregularsea-states and validate the latest hydrodynamic codedevelopments. A fully coupled numerical model was built from the tested vessels’ characteristics using ANSYS AQWA multi-body hydrodynamic analysis software.

The calculation of the relative slow-drift motionsbetween the moored vessels is critical for the designof LNG transfer systems having limited design excur-sion envelopes. Due to the intermediate water depth(60m), the slow-drift forces are estimated from a fullypopulated difference frequency quadratic transferfunctions (FQTF) matrix. In undertaking the modeltests, the propagation of wave groups in a closedbasin generates spurious long waves whose periodsare in the vicinity of the natural period of the mooredvessels. This significantly increases their response in the low-damped degree of freedom (surge). The low frequency wave elevation was measured and separated from the theoretical low frequency contentof the wave field. The additional forces resulting from these spurious waves were calculated andimported into ANSYS AQWA as a time history. The calculated LNGC slow-drift surge motionsobtained in head waves compare well with the experimental measurements.

included both the ocean below and the atmosphereabove the ship. Parameters including velocity, pres-sure and temperature were set before the CFD soft-ware solved the calculation iteratively. The results werethen analyzed using tabular information and still ormoving 3-D visualizations.

In this model scenario, the largest danger is normally considered to be the thermal radiation generated by the blaze, and the simulation makes iteasy to quantify the temperature at any location. Themodel can be adjusted easily to evaluate the impact of various scenarios, such as different weather conditions or a different size breach. Furthermore, itsconclusions could easily be applied to any geographicarea. Such information could prove invaluable in areas such as determining the location of future LNGterminals and emergency/disaster planning.

Improved Refinery DesignsAfter oil has been discovered, extracted and trans-ported, it enters a weblike maze of pipes, tubes, towers and tanks — the refinery. While refining is acomplex process, the goal is straightforward: to takecrude materials and transform them into the productsused for a wide variety of purposes. For oil, that usually means heating homes, fueling vehicles andrunning industry.

Petrobras, the government-owned oil company inBrazil, is one of the fifteen largest oil companies in theworld. Their research arm, The Research Center ofPetrobras (CENPES), joined with Engineering Simula-tion and Scientific Software Ltda. (ESSS) in the year2000 to develop projects using computational fluiddynamics (CFD) on upstream and downstream applications. ESSS is an engineering consulting firmand ANSYS support distributor in South America thatoffers custom CAE software solutions.

FLUENT software was used to model an LNG tanker explosion after a starboard breach. This images shows the LNG flame approximately two seconds after the start of the fire, illustrated through contours of temperature on an iso-surface of CO2.

Industry Spotlight


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Petrobras/CENPES uses ANSYS CFX to research inter-phase heatand mass transfer phenomena. This washing zone in a coke fraction-ation shows the behavior of vapor and liquid through the baffles.

LNG flame after about seven seconds

At CENPES, several studies require a thoroughunderstanding of inter-phase heat and mass transferphenomena. Some of these studies form the basis ofnew refinery projects such as coker and vacuum frac-tionators. These fractionators are used to separate the“heavier ends” of the raw crude oil into its componentparts, such as kerosene, diesel napthalene, etc. Petro-bras and CENPES have established a technical imper-ative to improve the efficiency of these fractionators.

To this end, with the assistance of ESSS, Petro-bras/CENPES enhanced the configuration of feed inletdevice fractionation towers and empty spray sectionsas well as tower internals. Such enhancements arebased on the study of spray injection characteristicswith complex physics and boundary conditions usingANSYS CFX software.

Further, to understand the best feed nozzle angle,spray distributions and operating conditions, theseenhancements take into account the heat and masstransfer between the different phases. Improvementswere made to the collector pans and liquid distributorsin the kerosene and light diesel sections using free surface models.

Petrobras/CENPES also has been performingadvanced studies that involve multiphase/multicom-ponent flows and free surface models applied usingEulerian–Eulerian and Eulerian–Lagrangian tech-niques. Researchers have employed a wide range ofmodels and boundary conditions to determine theoptimal design of these fractionators.

The positive results presented so far haveencouraged Petrobras to increase their use of ANSYSCFX software to solve a variety of additional engi-neering problems. Even with complex phenomena,using engineering simulation has produced very goodoutcomes; Petrobras/CENPES has been able toimplement improvements without the use of expensive, time-consuming experimental tests.

Targeting New Horizons

Technology will continue to advance global exploration, production and delivery of oil and gas:getting more out of each well, finding new pools,developing cost-effective materials and disturbing less of the environment. Global warming, government regulations, oil spills, sabotage and prolonged severeweather will undoubtedly shape the industry as well.

Each new discovery or invention will lead to anew set of challenges. But one thing is certain: Engineering simulation will be leveraged in a variety of applications in the oil and gas industry. ANSYS software has been a valued tool that many companiesin this industry have depended upon for years.Whether it’s modeling the extreme pressures of the

ocean floor or extracting the last bit of usable hydro-carbons from a barrel of crude oil, ANSYS technologycontinues to help these companies solve their diverseengineering problems. �

The author wishes to thank Paul Schofield of ANSYS, Inc. and Marcus Reis of ESSS for their efforts and contributions to this article.


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A Flash from the Past

Ancient cultures used crude oil in a variety ofways: to inlay mosaics in walls and floors, to linewater canals, to seal joints in wooden boats andto build roads. As early as 1500 BC, the Orient used specific oils as a technique for lighting, burning it slowly so it wouldn’t explode.The Chinese were the first to discover under-ground deposits of oil in salt wells; they transported the liquid in extensive pipelines madeof bamboo to use as a lighting source. TheRomans found a new use for the substances:they converted flaming containers of oil intoweapons of war. The control and availability of oiland gas played a major role in both World Wars.

The use of oil replaced coal as the world’sprimary source of industrial power early in thetwentieth century. Then in the 1950s, world oilconsumption began to grow at a rate of 7 percent annually; the forecast at that time indicated that oil reserves were equivalent to sustaining a short 30 years of production, leading many to fear that oil resources would beexhausted by the year 2000. In the 21st century,oil and gas production is now so high-tech thatmany of its techniques are used in other industries, including space exploration programs.


ANSYS, Inc. is rolling out the latest version of its familyof engineering simulation solutions with new tools and capabilities that enable users to complete jobs efficiently and fully leverage Simulation Driven Product Development for a wide range of applications.The release represents the leading edge in integrated,best-in-class engineering simulation functionality,including advanced analysis, meshing, optimization,multiphysics and multibody dynamics.

With the world’s largest simulation communityutilizing this software, ANSYS 11.0 brings togethertechnologies from existing businesses and recentacquisitions, making significant advances in :

� Developing and delivering best-in-class solvertechnologies

� Providing integrated coupled physics for complex simulations

� Exposing meshing technologies in a commonmeshing application, customizable for theuser’s physics and solver requirements

� Effectively handling larger problem sizes by supporting leading-edge hardware andsoftware platforms

� Evolving ANSYS Workbench as the best environment for CAE integration

� Establishing state-of-the-art computationalfluid dynamics technology within the ANSYSsoftware suite

The goal of our focused software developmentroad map is to provide customers with the mostadvanced and reliable engineering simulation solutions available in the industry. The following highlights illustrate some of the key new technologiesin ANSYS 11.0 that will increase user productivity andenable companies to continue broadening the role ofsimulation in the product development process.

Variational Technology for Solver SpeedupThe second ANSYS variational technology implemen-tation speeds up the solution and has been applied totwo distinct types of mathematical problems: non-linear solutions for structural and thermal analysis aswell as harmonic analysis. These capabilities arereferred to as VT Accelerator. This capability providesa 2X to 5X speedup for the initial solutions, dependingon the hardware, model and type of analysis used. VTAccelerator makes re-solves 3X to 10X faster forparameter changes, allowing for effective simulation-driven parametric studies of nonlinear and transientanalysis in a cost-effective manner. Users can makethe following types of changes to the model before aVT Accelerator re-solve:

� Modify, add or remove loads (constraints maynot be changed, although their value may be modified)

� Change materials and material properties� Change section and real constants

Expanded and IntegratedSolutions in ANSYS 11.0

New release brings together powerful enhancementsand new technologies to increase productivity andbroaden the role of simulation in product development.

By Barry ChristensonManager, Product MarketingANSYS, Inc.

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Images courtesy Aavid Thermalloy, ICT Prague and Silesian University of Technology–Institute of Thermal Technology.


� Change geometry, although the mesh connec-tivity must remain the same (that is, the meshmust be morphed)

VT Accelerator, at version 11.0, enhances the solution of the following types of nonlinear applications:

� Nonlinear structural static or transient analysisnot involving contact or plasticity

� Nonlinear thermal static or transient analysis

Mesh Morphing By working with a mesh and not the solid model, theANSYS Mesh Morpher allows parameterization ofmodels created from CAD data, nonparametric geometry data such as IGES or STEP, or mesh filessuch as the ANSYS .cdb file. Read a mesh into FEModeler and then create an initial configuration to“synthesize geometry” from the existing mesh. AtANSYS 11.0, the ANSYS Mesh Morpher allows fourdifferent transformations: Face Translation, Face Offset, Edge Translation and Edge Offset. A wide

variety of configurations can be created with thesetransformations. For example, a Face Offset of a cylindrical surface is equivalent to changing the radius.These translations determine target configurations andautomatically define transformation parameters.

OptimizationANSYS DesignXplorer has a powerful new suite ofdesign of experiments (DOE) tools. Automatic designpoints can be generated two ways: Central CompositeDesign (CCD) or Optimal Space-Filling. CCD providesa traditional DOE sampling set, while the objective ofOptimal Space-Filling is to gain the maximum insightwith the fewest number of points.

New meta-models can accurately represent highly nonlinear responses such as those encounteredin CFD or structures. After sampling, ANSYS DesignXplorer provides four different meta-models torepresent the simulations response: Full Second OrderPolynomial, Kriging, Non-Parametric Regression andNeural Network. Kriging has two variants, pure Krigingand Radial Basis Function.

With the new body-fitted Cartesian meshing algorithm in ANSYS11.0 software, a user can generate a pure hex mesh on even themost complicated geometries.

Today it is quite common to go from CAD geometry to a finiteelement mesh. At 11.0, within FE Modeler, you can transform amesh (left) into geometry (right) and then, with the ANSYS MeshMorpher, make it parametric — thereby making design studiesand optimization possible.

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Using the ANSYS fluid structure interaction capability, a thermal–stress simulation can be performed within ANSYSWorkbench. For this gas engine exhaust header, thermal loads were passed from ANSYS CFX software to ANSYSMechanical software to determine the heat transfer between the fluid and the solid body. From this information, the user determined stresses and ultimately performed afatigue analysis.

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Once you have the simulation’s responses characterized, ANSYS DesignXplorer supplies threedifferent types of optimization algorithms: Screening(shifted Hammersley), Multi-Objective Genetic Algo-rithm (MOGA) and Nonlinear Sequential QuadraticProgramming (NLPQL). At 11.0, ANSYS DesignXploreroffers a full suite of sampling, modeling and optimiza-tion routines to address a wide variety of applications.

Fluid Structure InteractionThe integration of ANSYS and ANSYS CFX technolo-gies in ANSYS Workbench has taken another step forward. With version 11.0, users will be able to set up,solve and post-process a two-way fluid structure interaction (FSI) simulation completely in the ANSYS

Workbench environment. The latest release also provides a single post-processing tool. ANSYS Workbench significantly reduces the time to obtainsolutions to complex multiphysics phenomena.

The General Grid Interface technology of ANSYSCFX software has been utilized to deliver FSI loadtransfers between ANSYS and ANSYS CFX that areboth conservative and profile-preserving. The robust-ness and accuracy of all FSI solutions are improved.This breakthrough in interface load transfer technologyis clearly one of the benefits of having experts in FEAand CFD working side-by-side, on the same team,sharing technology. The range of fluid structure interaction cases has expanded with release 11.0.

TurboSystem Vertical SolutionThe ANSYS Workbench environment provides an integrated geometry design and analysis system thatlinks all elements of the rotating machinery designprocess. ANSYS Workbench is the integration platform for advanced physics capabilities that enable designers to model rotating machinery such as pumps, compressors, fans, blowers, turbines,expanders, turbochargers and inducers. The integration of ANSYS solutions into the designprocess can take weeks out of the CAE process by eliminating manual file transfer, result translation and re-analysis time.

The first step in the turbomachinery designprocess is to obtain a preliminary design using initialsizing software, given the performance criteria and sizing constraints. PCA Engineers Limited is providinginitial sizing software for centrifugal compressors andpumps that will be included in ANSYS BladeModelerat 11.0. Vista-CC Design is a rapid mainline designprogram that — when given the compressor dutymass flow, pressure ratio and geometric constraints —configures the compressor scantlings, vane inlet andexit angles, velocity triangles. It also provides essentialnon-dimensional performance parameters, such asspecific speed and specific flow rate on which designdecisions can be based.

The inclusion of 1-D sizing tools, automatedmeshing, streamlined work flow and automatic reportgeneration all contribute to a simulation-driven designand analysis system that will enable users to developbetter turbomachines.

The integration of these tools is an example of theANSYS ongoing commitment to develop powerfulsolutions for specific industry requirements.

Integrated Meshing TechnologiesANSYS 11.0 delivers more examples of meshing technology integration and provides physics-

ANSYS DesignXplorer VT software’s new fitting methods, suchas nonparametric regression, are powerful enough to capturevery complex responses, as this example shows.

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based meshing solutions that tailor the mesh for mechanical, electromagnetics, CFD or explicit dynamics simulation. Best-in-class meshing tech-nology from ANSYS, ANSYS ICEM CFD and ANSYSCFX has been exposed within the ANSYS Workbenchenvironment to leverage the strengths of the variousalgorithms to provide an intelligent, flexible and robust solution to meshing.

Based on the defined physics filter, various controls are automatically defined, such as mesh size, mesh transition, mesh uniformity, mesh speed,mesh quality and refinement controls for proximity andcurvature. Advanced user controls then are availableto exert influence over the mesh when required. This intelligence in meshing allows even the noviceuser to get a good mesh suited for the defined physicswhile providing the flexibility of additional controls to improve the solution speed and/or accuracy. Themultiple meshing methods, available throughadvanced options, also provide backup meshingapproaches to improve the overall robustness of themeshing solution.

In 11.0, a common mesh data structure has beenimplemented that provides additional flexibility in theinteraction among applications within the ANSYSWorkbench environment. This development providesincreased bi-directional communication for interactionbetween solvers (FSI, implicit/explicit, etc.) as well as a more unified approach to meshing (geometry synthesis, advanced meshing). This common meshdata structure also provides a method for integratingthird-party mesh utilities within the ANSYS Workbenchframework.

New in ANSYS ICEM CFD and AI*Environment11.0 is a multi-zone volume meshing tool tailored forexternal aerodynamic applications. This new meshingapproach provides the flexibility and control of ablocking (structured meshing) approach with the easeof use of an automatic (unstructured) meshingapproach. This semi-automatic multi-zone meshingalgorithm allows a user total control over the mesh

features both on the surfaces as well as into the volume. Boundaries are created with mapped orswept blocks providing a pure hex mesh on theboundaries with transitions to tetrahedral or hex dominant/core in the interior. This flexibility of mapped,swept and free blocks provides the freedom to usestructured hex mesh in the most important regions ofthe model while getting a high-quality automatic meshin regions of less concern.

The ANSYS TurboSystem solution provides integrated tools fordesigning and simulating a wide range of rotating machinery within the ANSYS Workbench environment.

New mesh methods have been added to provide a uniform mesh with controlover minimum edge length asrequired for the ExplicitDynamics simulation. Physicspreferences allow the soft-ware to key off the physicsrequirements and apply smartdefaults to the mesh.

Inflation layer controls areavailable to put prism layerson surfaces of primaryimportance in the simula-tion. This allows a CFD userto capture the boundarylayer with a biased mesh to capture the Y+, or astructural user to create uniform orthogonal mesh onkey surfaces for improved accuracy in the simulation.

ANSYS ICEM CFD and AI*Environment 11.0products also address the age-old question, “Should Imesh with tets, or should I spend the extra time to create a hex mesh?” You can do both with the newbody-fitted Cartesian meshing approach that gives apure hex mesh in less time than traditional tetrahedralmeshing algorithms. Options also exist for a hybridmesh with tets and pyramids to reduce the constraintson the mesher and provide easier methods to edit the mesh. The uniformity of the hex mesh that is generated from this approach makes it perfect forexplicit crash analysis or any simulation in which uniform hex mesh is of interest.

Linear and Nonlinear DynamicsNew at release 11.0, ANSYS expands and consolidates its wide array of advanced structuraldynamics capabilities into a single ANSYS Workbenchenvironment. Linear and nonlinear structural dynamicsand stress analysis now are seamlessly integrated intoANSYS Workbench Simulation, bringing frequencyresponse and time history dynamics of rigid and flexible structures and mechanisms together. In a single setting, users now can select a range of

Structural dynamics and stress analysis are seamlesslyintegrated into ANSYS Workbench Simulation.

Image courtesy Dale Earnhardt, Inc. Engineering.

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behaviors: from linear to advanced nonlinear and from fully rigid to fully flexible responses, and all combinations in between. Other process-stream-lining features include support for simple andadvanced joints and constraints, geometry-basedautomatic joint detection, nonlinear materials and contact, kinematic analysis, and associativity withCAD system geometries.

ANSYS Community:New Release Information

We urge all customers to review the release information onthe ANSYS customer portal; in addition, we encourage you tovisit the ANSYS Community Forum area. This section in theforum contains detailed examples and how-to guides formany new features, all designed to help you start using thesetechnology enhancements quickly. To access the area, visitthe ANSYS Workbench Forum or ANSYS CFX Forum area andthen select “All Forums” from the menu on the left. SelectANSYS 11.0 Forum, which is displayed in the list.

ANSYS AUTODYN explicit analysis software for modelingnonlinear dynamics now is available as an integrated tool in theANSYS Workbench environment. In this simulation, the golf ballis created as a parametric model via ANSYS DesignModeler andmodeled with multi-layer, hyperelastic, Lagrangian components.The sand is modeled using the Smooth Particle Hydrodynamic(SPH) method contained in ANSYS AUTODYN.

The efficiency of the expanded ANSYS dynamicssolution makes it ideal for:

� Interactive part and assembly joint definitionand verification

� Determination of assembly dynamic responseunder pure rigid body assumptions

� What-if studies through parametric modelchanges in the CAD system or ANSYS DesignModeler

� Rapid evolution from rigid dynamic analysis topartial or fully flexible analysis

� Consolidating the complete dynamics analysisin one user environment — ANSYS Workbench

Explicit DynamicsANSYS AUTODYN software is a uniquely versatileexplicit analysis tool for modeling the nonlineardynamics of solids, fluids and gases and their inter-actions. At release 11.0, ANSYS AUTODYN will be available for the first time as an integrated tool in theANSYS Workbench environment. Tightly couplingANSYS AUTODYN with tools such as ANSYS Meshing and ANSYS DesignModeler provides anenvironment in which rapid decisions can be made based on results provided only by an explicitdynamics simulation.

With a graphical interface that is easy to use andis fully integrated into ANSYS Workbench, ANSYSAUTODYN allows setup, running and post-processingof problems and includes benefits such as:

� Associativity to solid geometry from CAD toolsor ANSYS DesignModeler

� Finite element (FE) solvers for computationalstructural dynamics

� Finite volume solvers for fast transient computational fluid dynamics

� Mesh-free particle solvers for high velocities,large deformation and fragmentation (SPH)

� Multi-solver coupling for multiphysics solutionsincluding coupling between FE, CFD and SPH

� A wide suite of material models incorporatingconstitutive response and coupled thermo-dynamics

� Serial and parallel computation on shared anddistributed memory systems

� Links to parametric CAD, ANSYS DesignModeler and meshed models as a nativeANSYS Workbench application, permittingrapid parametric studies without manual model updating

Integrated for Overall Product Development SimulationOther exciting new features in ANSYS 11.0 softwareare too numerous to list here. (See below, “ANSYSCommunity: New Release Information.”) The ANSYSdedication to solver technology, simulation processintegration and usability revolution will be clearly visible in many areas of this release — and in futureupdates as well. �

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In the rapidly changing electronics industry, designersare cramming ever-increasing capabilities into smallerand smaller products such as cell phones, PDAs andlaptops. Moreover, electronics is being integrated intoan expanding variety of formerly all-mechanical products. This pushes the limits of air cooling to protect sensitive circuitry from its number-one enemy:excessive heat build-up. In these demanding applica-tions, there is little time for mechanical, thermal andelectrical simulation in launching quality electronicproducts to meet narrow windows of market opportunity — and there is absolutely no room for failure. In this fast-paced, high-stakes industry, ANSYStools are used in meeting these challenges for thermalanalysis relating to chips, components, printed circuitsand complete systems.

Thermal Analysis

The electronics industry can be segmented into fourgeneral areas: chip, component, printed circuit board(PCB) and system. The chip is the part of the packagethat has active circuitry on it — and where the majorityof the heat is generated. Chips typically are made ofsilicon, gallium arsenide (GaAs) or gallium nitride.Active features on a chip can be smaller than a micron.

Many companies use the special features ofANSYS TAS software to thermally simulate GaAspower amplifiers. This feature allows RF design engineers to easily define the geometry. The full chipmodel is generated automatically with details to thesub-micron level. Typical solve time is less than a minute.

Simulating Electronic Components

To thermally simulate electronic components, ANSYSoffers ANSYS PTD, or Package Thermal Designer,software. For ball grid array (BGA)-type packages,

ANSYS PTD has direct interfaces to Cadence® APDand Sigrity® UPD, the leading ECAD tools used todesign these components. Every part of the design isimported from these tools, leaving little to be definedby the user. Three-dimensional models usually can beautomatically generated and solved in a few minutes.

ANSYS PTD tools can simulate almost any package style including BGA, multi-chip, leaded andleadless. Package-on-package (PoP)- and package-in-package (PiP)-type devices can also be simulated.These devices integrate multiple individual parts into asingle package. Complex geometry such as lead-frames can be imported through DXF or DWG MCADfiles. The component can be placed on a JEDECboard, and standard thermal characterization tests can be simulated accurately. With the easy-to-use

Latest Tools for ThermalAnalysis of ElectronicsA wide range of ANSYS software is available to study coolingin ICs, components, PCBs and complete electronics systems.By David RosatoProduct ManagerANSYS, Inc.

Rajesh NairManager, ICE DivisionFluent Inc.

Temperatures of a four-BGA package-on-package weredetermined by ANSYS PTD.

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environment, direct ECAD interfaces, fast geometryprocessing and model solving, simulations that oncetook days can now be done in minutes.

Studying Printed Circuits

At the printed circuit board level, ANSYS offersANSYS TASPCB technology. Like ANSYS PTD,ANSYS TASPCB has interfaces with the ECAD toolsused to design them. ANSYS TASPCB softwareimports every layer, trace, plane and via in the board.As components get smaller and their power dissipa-tion increases, the local thermal behavior of the PCBto which they are attached becomes more important.A PCB can have as many as 20 to 40 layers with tensof thousands of traces and vias. Each of these is alocal heat transfer path.

ANSYS TASPCB software accounts auto-matically for every one of them in the 3-D model of theboard that is automatically generated. As power dissipation on the board increases and operating voltages decrease, the current going through theplanes and traces increases. This causes a voltagedrop in the traces and planes that turns into heat.ANSYS TASPCB can calculate this voltage drop andautomatically make the dissipated heat part of theoverall thermal solution. The solution also accounts forhow the electrical resistance of copper significantlychanges with temperature by increasing the heat generated with increased temperature.

The 3-D models generated by ANSYS TAS,ANSYS TASPCB and ANSYS PTD software can be exported to ANSYS Mechanical software and theANSYS Workbench environment. Temperature results are included, permitting thermal–stress simulation. A simplified version of the ANSYS TASPCB board withcomponents and power can be exported to Icepaksoftware, the electronics cooling design tools that arenow part of the ANSYS suite from the company’srecent acquisition of Fluent Inc. The componentgeometry from ANSYS PTD also can be exported toIcepak for system-level analysis.

System-Level Design and Optimization

Icepak software is interactive, object-based thermalmanagement software for performing thermal designand optimization at the system level. The technology’smodel-building features include search and selectionfrom libraries of pre-defined parts and components,placement and sizing using the mouse, and use ofcomplex geometries including direct import from CAD

tools like ProEngineer® or ECAD tools (Cadence, Mentor®) if necessary. Predefined object models likeheat sinks, integrated circuit packages, PCBs, fansand blowers allow users to rapidly build a system prototype even before designs are committed to CAD.

A variety of advanced physical models —including those for turbulence, flow and temperatureresistance modeling, radiation, shell conduction, andheat exchanger models — make Icepak software thestate of the art in thermal modeling. Network modelingoptions allow the user to optionally represent complexIC packages using simple RC-type network models.Automated meshing algorithms take user input in the form of local (object-based) and global sizes and generate a high-quality mesh. Assembly-levelmeshing allows the user to include minute details in asystem-level model yet keep the model sizes smalland solution times short. The backend solver, providedby Fluent, is robust and fast.

Evaluating IC Package Designs

Icemax software is an advanced parasitic extractiontool for analyzing complex IC package designs.Increasing circuit and transistor density has led toproblems of cross-talk and signal integrity that cannotbe easily analyzed using design rules or correlations atthe package level.

The Icemax modeling interface is trivially simple.It eliminates the major bottleneck in the model-building process by being compatible with all EDAplatforms that are used across the IC design industry.A full three-dimensional model is generated in a matterof minutes from industry-standard layout data using

Temperature and air flow in this server system with blowersand heat sinks were predicted by Icepak software.


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super-fast geometry processing engines. Model-building tasks then get reduced to a simple sequenceof events that include importing layout information;assigning material properties; and including additionalinformation like wire bonds, solder bumps and solderballs. This is performed through a wizard-style inter-face that leads the user through the steps required tocomplete the 3-D package geometry. The user merelyneeds to specify the operating frequency, the net (orthe entire package) to be simulated and the number ofneighbors to be included in the simulation.

Package designers, engineers and researchersinvolved in IC package design can easily generatedetailed, reliable RLC information for the entire package in a matter of minutes. Output can be generated in matrix, SPICE or IBIS formats for signal integrity, power integrity and simultaneousswitching noise analysis. The output is ready for circuit simulation.

Full Wave Simulation for EMC and EMI

Icewave software is a time-domain 3-D full wave simulation tool for EMC and EMI analysis of electronicproducts. Icewave uses a robust finite-difference timedomain (FDTD) field solver to solve complex real-worldelectromagnetic (EM) radiation and propagation problems. EM radiation problems have becomeincreasingly important for the average consumer

because of stringent regulations regarding electro-magnetic emission and specific absorption rate (SAR).Issues related to cross-talk are experienced when EMradiation from one device interferes with the operationof another device. Additionally, use of cooling deviceslike heat sinks in order to solve thermal problems atthe packaging level result in these devices behavinglike antennae, thereby compounding the problem ofminimizing EM radiation. Furthermore, a thermal solu-tion for a system usually tries to maximize the flowthrough the system by ensuring larger intakes andexhausts from the system; however, this works atcross-purposes with an EM system design that tries tominimize radiation from the system by closing off orminimizing the size of these openings.

Icewave technology shares its CAD import capabilities with Icepak, thereby allowing import froma variety of CAD tools and formats. Model-buildingcapabilities are similar to those of Icepak, allowingusers to build relevant parts like heat sinks, enclosures, vents, sources and lumped elementsquickly and efficiently without having to start withbasic entities. Mesh generation is fully automated.Advanced material models such as dispersivedielectrics and frequency-dependent skin effects onconductors also are available. �

Icemax was used to extract SPICE models for thismulti-chip module.

Icewave was used in determining the electric fieldin this electronic enclosure.


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Finite element analysis (FEA) is widely used in thedesign of new turbine products. The technology historically has been weighted toward the start of the product’s life, the point at which optimizations are necessary and the design is still in flux — in otherwords, before production begins. Later in product life,the use of FEA has, by and large, been limited to dispositioning discrepant hardware or conducting lifeupdates, as turbine components in the field approachtheir original life limits on-wing.

Recently, the philosophy of life management ofaging aircraft turbine engines and airframes haschanged. A new paradigm called condition-basedmaintenance (CBM) is the new focus. This approachdiagnoses a part’s remaining health and life by analyzing measurable phenomena such as suddentemperature or performance excursions, or minute butdetectable vibration signatures. The aim is to identifyindicators that precede significant component lifeevents, such as creep or fatigue failure.

The promise of reducing life-cycle costs is basedon the premise that the consequences of a crack orimminent failure detected with CBM can be avertedthrough comparatively inexpensive maintenancebefore more costly component field failures occur.Using the same premise, reliable prediction and earlydetection of component failure also will make it possible to keep expensive critical components on-wing longer.

Why ANSYS Software was Selected

The key word here is reliable, and the best way toensure reliability is to embrace FEA as a key life-cyclecost management tool. Peregrine Consulting, Inc. hasbeen engaged in research for three years under a contract with the U.S. Air Force to address the challenges in making possible (and even economical)real-time stress and life analysis of turbine compo-nents for as-flown conditions.

Simulation-Based Life-CycleCost ManagementANSYS Mechanical performs stress and thermal analysisfor calculating as-flown fatigue life of critical jet engineturbine components.

By David StappPresident Peregrine Consulting, Inc.U.S.A.

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Peregrine chose ANSYS Mechanical as the coresolver because of its broad capacity for customizationand its abundance of tunable parameters, as well asthe fact that ANSYS, Inc. is a true veteran of aircraftturbine design and analysis. The software has beenthe tool of choice at turbine OEMs since the early 1980s. When Peregrine Consulting set aboutdeveloping ground-breaking technology, we decidedthat using a proven tool as a core element would ease the substantiation process and guarantee theusability of legacy data, a significant advantage.

ANSYS also has shown substantial commitmentto continual improvement of its solver technologies.Case in point: Improvements in the Distributed ANSYSproduct allow us to run solutions efficiently in parallelacross multiple CPUs. Enhanced scalability of solverperformance directly impacts the return on investmentof managing turbine field life, and ANSYS has demon-strated a commitment to being first-to-market withnew solver features.

Analyzing Parts As-Manufactured, As-Flown

In analyzing turbines for true in-service usage conditions, determining what missions should be analyzed, especially for military turbines, is a significant undertaking. In addition, it is a disciplinethat is revisited frequently over a turbine’s life-cycle.Defining a representative sample of expected missionsfor a fighter aircraft turbine is no small task. Since

throttle excursions may be abrupt and unpredictablefrom flight to flight, arriving at methods to calculatefatigue damage to critical components takes consider-able manpower and engineering judgment.

Calculating as-flown, as-manufactured fatiguedamage for each part and each flight reduces relianceon engineering judgment. It will extend on-wing component life for a considerable population of turbines while catching outliers that could result in apremature failure. To be sure, managing analysis and data on this scale is a challenge, but with littleassociated risk and substantial cost and reliability benefits to be gained.

Considering the high cost of turbine componentsand the cost of taking valuable assets out of servicefor repair, there is a tipping point at which the life-cyclecost savings derived from acquiring and managingdata on that scale is worthwhile. At Peregrine Consulting, we believe the time has arrived to economically run near-real-time analysis of as-flownmissions for every turbine in the field. The implicationsto the safety of military aircrews and the flying public,as well as the impact on the life-cycle costs of veryexpensive assets, could be dramatic.

Multiphysics Engine Simulation

Peregrine Consulting’s three-year development efforthas resulted in a prototype of the core application for Turbine Field Life Analysis Multiphysics Engine Simulation (TFLAMES): a specialized data processing

Peregrine Consulting, Inc. created thiscomplex model of the high-pressure turbinerotor through ANSYS pre-processing capabilities. Detailed analysis accounts for effects such as frictional contact,stress-stiffening and large deformations.

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and process management program that calls uponANSYS tools to do the heavy lifting of frictional-contact rotor assembly stress analysis. Our prototypefeatures the high-pressure rotor of the F414 turbine,the Navy’s engine for the F-18E/F Superhornet.

We combined disparate models created separately (most of them by our own engineers) into a single high-pressure rotor model, eliminating the cut boundary condition issues normally associatedwith turbine rotor analysis. Previously, this was anuntenable approach for a frictional analysis due to the large element count and the difficulty of reachingsolution convergence. But with efficient solvers, proprietary techniques and cost-effective high-performance compute platforms, full turbine rotoranalysis of as-manufactured geometry becomes aneconomical reality.

Analyzing Actual Aircraft Missions

A question arises once the model is defined: Howdoes one analyze an actual aircraft mission? The typical turbine-powered aircraft already stores theflight mission data in its engine controller, so gettinginformation about flight conditions (such as ambienttemperature and pressure, airspeed, turbine rotorspeeds, etc.) is relatively straightforward. TFLAMESwill screen input for data problems, determine suitabledata sets for analysis and then convert that data foruse as input to heat transfer and stress analysis.

Once a complete set of stress and temperatureresults for a single mission is at hand, fatigue damage

for each critical turbine location can be calculated at alevel of accuracy not previously achievable. In fact,TFLAMES will make it possible to understand theeffect of a wide range of factors that may impact turbine component life, such as pilot practices, manufacturing tolerances and aberrations, missioncomplexity, material fatigue capability and environ-mental conditions. In this way, data mining of theresults will yield new understandings of the key factorsthat lead to long component lives.

By combining Peregrine’s proprietary simulationacceleration techniques with low-cost, high-performance servers and the ANSYS software capability to process runs across multiple CPUs, it hasbecome economical to run full rotor transient analysiscapturing nonlinear effects such as frictional contact,stress-stiffening and large deflections in a period oftime measured in hours rather than weeks — a majorstep forward in life assessment technology.

The TFLAMES approach to product life-cyclecost management can be employed when the asset isexpensive to maintain or difficult to access, or whenin-service conditions are hard to pin down: areas suchas space vehicles, satellite structures, permanentspace platforms and even planetary infrastructureassets of the future. �

Peregrine Consulting, Inc. (www.peregrineconsulting.com)provides design and analysis consulting services for the aerospace industry in areas such as turbine enginedevelopment, unmanned aerial vehicle design, enginesystems integration and fatigue life studies.

Condition-based maintenance uses FEA to predict component life for components in jet turbine engines such as the F414 powerplantfor the F-18E/F Superhornet aircraft.

CFD Helps Design an Environmentally Friendly CarFiat Panda MultiEco show-car uses aerodynamic studiesto reach fuel efficiency goals.

By R.Tregnago, Head of Aerodynamic and Aeroacoustics, Vehicle Division

E. Ribaldone, Senior CFD Engineer

R. Putzu, Junior CFD Engineer

Centro Ricerche Fiat, Italy

Fiat considers the Panda MultiEco to represent thefuture of environmentally friendly cars. Introduced during the 2006 Geneva Motor Show, this concept carexhibits leading technology to reduce emissions and decrease fuel consumption by combining an innovative “powertrain” architecture, the use ofeco-compatible materials for the exterior and interior,and aerodynamic improvements and optimization.

Developed within the Fiat Group (Fiat Auto, FiatPowertrain Technologies and Centro Ricerche Fiat),these solutions will bring great benefits to consumers.Thanks to lower fuel consumption and the use of low-cost methane, the Panda MultiEco reduces relativecost per kilometer by an impressive 63 percent.

Aerodynamic studies of the Fiat Panda MultiEcowere performed by Centro Ricerche Fiat (CRF), an industrial organization whose objective is the

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Panda MultiEco represents the future of environmentallyfriendly cars, according to developer Fiat. The companyused ANSYS technology to analyze the concept car’saerodynamics. All images courtesy Centro Ricerche Fiat.

promotion, development and transfer of innovation to provide a competitive advantage to clients and partners. These include the different companies in theFiat Group, automotive suppliers, companies fromother sectors of industry, small and medium-sizedenterprises (SMEs), and national and internationalresearch agencies. Priority areas for R&D at CRFinclude energy and environment, safety and well-being, and sustainable growth. The core competenceof CRF is centered on land transportation, whichincludes advanced vehicles and propulsion systems,innovative components and their associated manufac-turing processes, and methodologies for productdevelopment.

For this project, the goal with regard to aerody-namics was to achieve a drag coefficient for the PandaMultiEco that was lower than the standard Panda vehicle. The design concept for the MultiEco wasbased on the Panda 4x4, because the height of the4x4 more easily allowed the introduction of methane(compressed natural gas or CNG) tanks in place of differential and rear-wheel powertrain shafts. However, the Panda 4x4 has the highest drag coefficient of the entire Panda family; therefore, reaching the target reduction was quite challenging.

Aerodynamicists of Centro Ricerche Fiat anddesigners from Centro Stile Fiat worked together fromvery early in the design process to try to reconcile stylewith aerodynamic requirements.

Considerable effort was spent improving theunderbody aerodynamic efficiency. Fully detailedgeometry models were considered, using computa-tional grids generated with ANSYS ICEM CFD software. The cases were run using grids consisting of

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Flow streamlines (colored by velocity) along the vehicle underbody

several million tetrahedra and prisms. CFD simulationsof underbody components using ANSYS CFX meshing software focused on highlighting and reducing the most significant contributors to aero-dynamic drag. The results were useful in designing fairings, shields and a rear diffuser. The huge amountof CFD analysis throughout the vehicle developmentprocess also allowed definition and refinement ofdetails like the rear spoiler and front bumper.

A first study was performed on a Panda 4x4 car.This case was considered as an aerodynamic reference for subsequent tests. Further analysis, performed on several Panda MultiEco concepts, wereuseful in highlighting critical regions and componentsthat affect flow behavior. In particular, the presence ofthe gas tanks on the underbody of the CNG vehiclewas shown to have significant impact on the overallvehicle aerodynamic performance. Increasing this performance was achieved by optimizing dam shape

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Reducing drag on the underbody of the Panda MultiEco was animportant consideration in ensuring reduced fuel consumption. This graphic shows the velocity field on a slice plane through the vehicle.

Normalized drag forces, comparison between Panda 4WD andselected Panda MultiEco designs

Velocity contour on a slice plane through the vehicle underbody

and dimension, introducing and optimizing a rearspoiler, conveniently shielding the underbody cavities,and designing an appropriate rear diffuser.

Important reductions in drag were obtained bothon the underbody and the rear car body. The ultimate relative reduction of the drag coefficient was estimatedto be 18 percent of the initial Panda 4x4 value, providing an absolute drag coefficient that met the desired value.

Virtual simulations performed with ANSYS CFXplayed a fundamental role in supporting engineeringdecisions during the project. Moreover, using CFDallowed CRF to save time and money by avoiding theprototyping and testing costs that would have beenincurred for experimental investigations in an aerody-namic wind tunnel. The use of ANSYS CFX during thedesign cycle of the fuel-efficient Fiat Panda MultiEcowas instrumental in allowing the team to reach theaerodynamic goals. �

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Simulation at Work

A name known in households since 1920, Murray, Inc.is a global manufacturer of lawn, garden and outdoorpower equipment that includes snowthrowers, lawntractors, walk-behind mowers, gas-powered edgers,mini-cultivators and high-wheel trimmers. Headquar-tered in Brentwood, Tenn., U.S.A., the company takespride in offering products that provide consumers thelatest technology, greatest durability and top designsfor the money. Products are powered by engines fromBriggs & Stratton, the world’s largest producer of air-cooled gasoline engines for outdoor power equip-ment. Briggs & Stratton expanded its product portfoliowith the recent acquisition of Murray, Inc.

One of Murray’s newest products is the Power 2Steer, a heavy-duty snowthrower with a unique steering system that enables consumers to maketurns easily, compared to competitive equipment thatforces users to squeeze a trigger, which releases drivepower to one of the two wheels. This action requiresconsiderable dexterity and effectively reduces tractionby 50 percent, because only one wheel is being driven. In contrast, consumers can turn the MurrayPower 2 Steer simply by adding pressure to the handle. This engages a proprietary clutch assemblythat provides the proper variable-speed driving forceto the wheels for easy turning and steering. In this way,the Power 2 Steer gives twice as much power as thecompetition because traction is maintained on bothwheels, not just one.

Hitting the Window of Opportunity

Murray had only a few short months to get the Power2 Steer into production before the company lost busi-ness from one of its strategic snowthrower retailers.Hitting this narrow window of opportunity just beforethe snow season would be difficult, because the effect

Development of an InnovativeMurray/Briggs & StrattonSnowthrower Steering SystemITI Manta used ANSYS Mechanical in designing components for optimal fatigue life.

of the new clutch assembly on stress and deflectionlevels needed to be evaluated for components andsubsystems throughout the snowthrower, such as the drive shafts, bearings, subframe and sheetmetalmain chassis.

Designing these components for the necessarystrength was critical to ensure adequate fatigue life of components without adding prohibitive cost andmaterial. The tight product development schedule leftno room for numerous physical prototype test cycles.

Simulation-Driven Design

To meet the production deadline, Murray turned to ITIManta for engineering analysis of the structure and

ANSYS Mechanical software was used by ITI Manta in its simulation-driven design approach for developing parts such as this snowthrower auger shaft.

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design of critical components and subsystems. ITIManta is the test, analysis and design business withinproduct development consulting firm InternationalTechneGroup Incorporated (ITI, www.iti-global.com).

The firm used ANSYS Mechanical software todetermine von Mises stress and structural deflection ina simulation-driven design approach, in which flawsare spotted, alternatives are explored and product performance is refined early in the conceptual stage ofdevelopment before detailed design is created and thefirst prototype built. Using this approach, componentdesigns were optimized based on minimizing stressand deflection levels and, thus, optimizing the targetfatigue life. Hardware prototypes then were built toverify the design.

“ANSYS software was essential in the simulation-driven design approach used in analyzing and developing components and assemblies for the Murray Power 2 Steer snowthrower,” explains Brian Lewis, product development manager at ITI. “Parametric capabilities allowed us to quickly changemodels to study alternatives without remeshing fromscratch. Also, the software worked extremely well withother packages in providing a convenient way to integrate structural analysis into a virtually seamlessproduct development process from concept throughrelease to manufacturing.”

Significant Benefits

By parameterizing simulation models, ITI Manta engineers were able to quickly modify the designs to meet the various operational requirements and iteratively arrive at an optimal product configuration. Inthis way, the design was completed on time to meetthe seasonal product launch.

Since its introduction, sales volume for the Power2 Steer snowthrower has continued to grow thanks tothe steerable feature, which the company describes asextremely successful in selling profitably over thecompetition. Product cost was minimized thanks tocomponent designs that minimized the amount ofmaterial used. In the long term, greater durability willcontinue to strengthen the company’s brand value inproviding customers with products designed and builtto last for decades. �

Simulation at Work

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The European Union has introduced emissions regula-tions for various vehicles during the past several years.In 2006, the Euro 4 regulations were targeted at newlight-duty vehicles with the goal of reducing NOx emissions and harmful particulates. To meet the newemissions targets, after-treatment devices have beenadded to the exhaust system of the IVECO Daily line of trucks and vans, one of the most popular lines oflight-duty vehicles in Europe. Engineers from IVECOand the Exhaust System Division of Cornaglia workedtogether to design the new exhaust system, usingFLUENT software CFD to optimize the flow distribu-tion in the catalytic converter (referred to as “cat”)while keeping the system backpressure under control.

A baseline exhaust system was studied first,focusing upstream of the muffler, where higher temperatures exist and the main contribution to thesystem backpressure occurs. The geometry then wasmodified and new calculations were performed tooptimize the following parameters:

� the flow uniformity index, γ, evaluated on inletsections of the pre-cat and main-cat monolithsand defined as the average of the deviationsbetween the mean and local flow velocities

� the system backpressure, or difference between the static pressure on the inlet section of the system and the ambient pressure

A 600,000-cell mesh was generated using GAMBIT, geometry and mesh generation software thatis now part of the ANSYS suite from the recent acqui-sition of Fluent Inc. The pipes and monoliths weremodeled with hexahedral elements, while the conicalsections were modeled with tetrahedra. Steady-state

calculations were performed using the k-ε turbulencemodel with non-equilibrium wall functions. The idealgas law was used for the exhaust gases, and heattransfer at the walls was included. The monoliths weretreated as porous regions, and the upstream mufflerstatic pressure, measured on an engine bench, wasused for the exit condition. Mass flow rates of 20 percent, 60 percent and 100 percent of the maximumflow rate of the IVECO F1C JTD engine were used asinlet conditions.

Four geometric configurations were analyzed to study the effect of different designs on the flow uniformity index and backpressure reduction. Oneconfiguration was found to perform the best overall,causing the most uniform flow for all but one flow condition and a 12 percent reduction in back-pressure compared to the baseline. The predictedimprovement was confirmed by experimental tests,and this configuration was subsequently adopted for serial production. The Cornaglia exhaust system,optimized by this study, is currently mounted on theIVECO Daily light-duty vehicles throughout Europe.The use of CFD for the optimization process reducedthe development time and the cost of prototype manufacturing. �

By Alessandro Verdi, IVECO Engineering Andrea Renzullo, Alessio Tarabocchia, Giorgio VillataCornaglia R&D, Italy

CFD Helps Light-Duty TrucksMeet New European EmissionsRegulationsFLUENT simulation optimizes flow distribution in catalytic converters while reducing system backpressure.

The Euro 4 baseline exhaust system Surface mesh used for the baseline system Pathlines colored by velocity magnitude illustrate the flowthrough the baseline design and an alternative design.

Simulation at Work

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Jyoti Ltd. has continuously widened its range of pumpsto meet the growing and constantly changing require-ments of the industrial pump market. Computer-aidedengineering as well as pump model testing facilities areinstrumental in helping the company develop pumpingsystems with superior hydraulic and mechanical performance. Jyoti uses ANSYS turbo system products to quickly and efficiently bring these newproducts to market.

Established in 1943, Jyoti Ltd. is a leading engineering company offering reliable quality productsand services to clients in India as well as the inter-national market. The company serves a wide range ofindustries, including power generation, transmissionand distribution; agriculture; water supply and sewagesystems; defense with a focus on naval and marineestablishments; railways; and core industries such assteel, cement, paper, sugar, fertilizers, chemicals andpetrochemicals.

Engineers at the CFD Analysis Center at Jyotiwere asked to assist in the design and development of

Meeting Market Requirementsfor Industrial PumpsANSYS tools for rotating equipment help designers decrease pumpsize by 33 percent while boosting performance for a power savingsof 5 percent.

By Anil Patel, Assistant General ManagerKiran Patel, Design Engineer, CFD Analysis CenterJyoti Ltd., India

a new pump based on an existing design. This pumpwas required to have increased efficiency as well asreduced manufacturing costs. Because ANSYS, Inc.provides an integrated system for design and analysisthat can greatly reduce the amount of time between

Testing facility at Jyoti Ltd. R&D Center, where CAE and pumpmodel testing facilities are used to develop pumping systemswith superior hydraulic and mechanical performance. Engineersthere used ANSYS technology to design a new pump based on an existing design.

All images courtesy Jyoti Ltd.

ANSYS CFX simulation of the old version of the pump (left) and the new version (right). The new design increased efficiencyand decreased cost.

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design iterations, ANSYS turbo system products wereused for this project: ANSYS CFX computational fluiddynamics software, ANSYS BladeModeler bladedesign tool and ANSYS TurboGrid rotating machinerymeshing product. These tools have long been in usewithin the rotating machinery community to reliablyprovide performance results.

Theoretical design of rotor and stator was completed using a conventional method, and then thedesign was transferred to ANSYS BladeModeler. The design was improved using ANSYS CFX analysisuntil the CFD analysis result parameter trends met thespecified requirements.

After several iterations and analysis using ANSYS CFX, the hydraulic performance of the equipment was greatly improved. This improvement

will lead to power savings of approximately 5 percent. Of even greater importance, the total weight of equipment as well as the material costs for these components was reduced by 33 percent, which isconsidered a major breakthrough for Jyoti.

In addition, simulation using ANSYS CFX software provided additional insights into the effect of incidence angle and secondary flow in the stator on the equipment performance. This resulted in performance improvements by optimizing secondaryflow in the stator and minimizing the incidence angle.In this way, through use of the integrated system ofrotating machinery tools from ANSYS, Jyoti was ableto both improve performance of the pump anddecrease costs. �

Blade loading at 5 percent span for old design (left) and new design (right)

Blade loading at 95 percent span for old design (left) and new design (right). The figure on the left shows stator blade loading for the old design at which the pressure on both side surfaces of blade cross. This would cause higher head loss and decreased performance. This design flaw has been corrected in the new design on the right and has improved the performance of stator.

Old pump design (left) and new pump design(right). The new design is 33 percent lighterthan the old design and is considered a majorbreakthrough at Jyoti.

993 765

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Simulation at Work

IHS ESDU International provides validated engineeringdesign data, methods and software that form an important part of the design operations of companieslarge and small worldwide. ESDU has more than 65years of experience in providing engineers with theinformation, data and techniques needed to continuallyimprove fundamental design and analysis. Guided andapproved by independent international expert commit-tees and endorsed by key professional institutions,ESDU methods are developed by industry for industry.ESDU International provides validated, up-to-date engi-neering data to design engineers and teachers ofdesign in the aerospace, mechanical, chemical andstructural engineering fields.

ESDU’s Thermofluids group has developed methods for calculating pressure losses in internal flowsystems for more than 37 years. These are industry-standard methods based on the analysis of high-qualityexperimental data, analytical methods and lately validated using ANSYS CFX software. Within ESDU,computational fluid dynamics (CFD) is used to supplement and support experimental methods of data collection.

Pipes with sudden contractions exist in manyengineering applications, including nuclear reactorcores and pipe fittings. To design such systems, thepressure loss and the extent of the flow separationsmust be determined to avoid placing sensitive equip-ment in the recirculation regions. There has been anincreasing need to predict pressure loss reliably forcases in which experimental data is not available, not reliable or inconsistent. There is little reliable experimental data on pressure loss in sudden con-tractions, especially for round- and chamfer-edged sudden contractions.

For CFD to reliably predict pressure losses andflow characteristics in internal flow systems, it isessential to capture the important flow mechanismsfor a wide range of geometrical configurations and flow conditions. The pressure loss and flow

Pressure Loss in Pipes with Sudden ContractionsANSYS CFX was used to validate an experiment correlating pressure loss and flow characteristics.

By Dr. Francesca Iudicello, Thermofluids EngineerESDU International plc, London, UK

characteristics correlations, recently developed byESDU, are based on rigorously validated CFD data forsharp-, round- and chamfer-edged sudden contractions in laminar, transitional and turbulent flow regimes. CFDvalidation studies in support of these correlations werecarried out using ANSYS CFX 10.0 software.

ESDU’s Thermofluids group was advised to use ANSYS CFX by the members of ESDU’s FluidMechanics, Internal Flow Panel, who have a deep knowledge of fluid mechanics and long experience in thedesign of internal flow systems. Under the guidance ofthis panel, ESDU is developing best practice guidelinesfor the use of CFD in the prediction of pressure loss andflow characteristics in internal flow systems.

Analysis of Turbulent Flow

The ANSYS CFX solver proved to be very robust, and it converged to a high accuracy within a reasonable number of iterations even with meshes that are not high-quality.

The resulting predictions were validated againstwell-documented, reliable experimental data using a rigorous procedure that reduced the sensitivity to mesh size and distribution, advection schemes, time-dependence, residuals levels, turbulence modeling and near-wall treatment, and flow boundary profiles andlocation. This procedure was applied to all geometricalconfigurations and flow conditions tested.

Three turbulence models were tested: the k−ε modelwith scalable near-wall treatment as well as the k−ω model and SST with automatic near-wall treatment.The closest agreement with the experimental data wasobtained using the SST model (automatic) for the flowseparation details, and with the k−ω model (automatic)for the pressure loss.

The validated ANSYS CFX predictions were withinthe experimental uncertainty. The results confirmed that itis essential that the pressure loss coefficient, determinedfrom the pressure drop across the upstream and down-stream pipes of the contraction, is calculated in

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the regions of fully developed flow outside the regionof influence of the contraction. These could be up to 110 diameter lengths (for high Re laminar flow)downstream of the contraction plane.

Better Understanding of Correlation

The ANSYS CFX results have helped us understandwhy the previous ESDU correlation for the pressureloss coefficient in turbulent flow was significantly higher than the ANSYS CFX predicted values. Theoriginal ESDU correlation and other commonly usedcorrelations are biased toward the widely used experimental data of Benedict. This information isreputed to be very reliable. However, the location atwhich the downstream static pressure measurementswere carried out is reported to be at the flow reattach-ment point and is assumed to be in fully developedflow. This assumption is not correct, as CFD calculations and measurements show that the flowbecomes fully developed at least 20 diameter lengthsdownstream of the contraction plane. It reattaches atabout one diameter length. Consequently, ANSYSCFX predictions are lower than Benedict’s data in thefully developed region but in close agreement at theflow reattachment point.

Comparisons of the ANSYS CFX predictions withthe pressure loss coefficient correlations in commonlyused engineering handbooks showed that althoughsome discrepancies are evident, they are in goodagreement with Bullen’s experimental data, which isconsidered reliable.

Traditionally, the ESDU database has been experimental and analytical. After the successful validation work on sudden contractions, ANSYS CFXdata will play a great role in the improvement of existing pressure loss correlations for internal flow systems. The results obtained with ANSYS CFX software, in some cases, proved to be more reliablethan previously accepted references. These CFD predictions explained the discrepancies and have provided guidelines for experiment. The success of thevalidation work for the pressure loss across suddencontractions has given ESDU the confidence to useANSYS CFX for other internal flow components, suchas orifices and valves. �

References

ESDU 05024, “Flow through Sudden Contractions of Duct Area: Pressure Losses and Flow Characteristics,” 2005-DEC-01.

ESDU TN 06023, “CFD Validation Studies for Pressure Loss and Flow Characteristics in Sudden Contractions,”ISBN: 1 86246 600 9. DOI: 10.1912/ESDUtn06023.

www.esdu.com

Flow schematic to determine pressure loss and extent offlow separation

Images courtesy ESDU International plc.

Typical ANSYS CFX results vs. experimental data were withinthe experimental uncertainty.

CFX results vs. Benedict’s experimental data. ANSYS CFX predictions are lower than Benedict’s data in the fully developedregion, but in close agreement at the flow reattachment point.

ANSYS CFX results vs. handbook correlations and Bullen’s experimental data. ANSYS CFX predictions are in good agreementwith experimental data.

Technology Update


In large-deformation analysis, two major problems cancause convergence difficulties and reduce simulationaccuracy (especially in static analysis with implicit solvers): mesh distortion and structural instability. A special nonlinear technique called rezoning was released in ANSYS 10.0 for the first ofthese problems, allowing users to repair the distortedmesh (limited to 2-D for now) and continue the simula-tion. In addition, a nonlinear stabilization techniquedeveloped as an enhancement in ANSYS 11.0 allowsfor state-of-the-art simulations of unstable nonlinearproblems such as post-buckling, snap-through, structural wrinkling and other analysis in which materials become unstable.

Numerical Damping for Large Deformations

An unstable structure usually is characterized by aload-displacement curve in which the deformations

Understanding Nonlinear Stabilization FeaturesEnhancements in ANSYS Mechanical handle nonlinear problemssuch as buckling, structural wrinkling and other large-deformationanalysis in which material behavior becomes unstable.

By Roxana Cisloiu and Jin WangANSYS, Inc. Development

can become very large during a small load increment.The newly developed tool in version 11.0 deals withsuch instabilities by providing a numerical dampingscheme invoked by the STABILIZE command, whichactivates or de-activates stabilization from one loadstep to another or after a multiframe restart during aload step. The stabilization feature can be thought ofas adding an artificial damper or dashpot element ateach node of an element for which this feature is available. Stabilization is achieved by reducing thelarge displacement of the node by adding to the forceequilibrium equations a damping force (stabilizationforce) proportional to the pseudo-velocity of the node.

Since it is usually difficult to predetermine the stability of a structure, it is more efficient and accurateto run the nonlinear analysis without stabilization whilesaving the restart files. Then, if the analysis fails toconverge due to instabilities, the stabilization can be

The nonlinear stabilization techniquecan be used in a wide range of unstableproblems, including some that would be difficult to solve with conventionalFEA methods.

Figure 1. Fuel containerexample geometry andboundary conditions

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Sample Problem: Collapsed Fuel Container


33

activated during a restart analysis from any substepexcept the last converged one. If the behavior of aproblem is known to lose stability very soon after theload application, then the stabilization can be turnedon at the beginning of the analysis.

The stabilization force can be controlled via anenergy dissipation ratio (STABILIZE,,ENERGY) or a damping factor (STABILIZE,,DAMPING). ANSYS provides the user with the option of applying the stabilization force by keeping the damping factorunchanged during each substep of a load step (STABILIZE,CONSTANT,) or by gradually reducing it to zero at the end of the load step (STABILIZE,REDUCED,). The specific value that has to be appliedto achieve both convergence and correct deformationpatterns is determined through a trial-and-errorprocess.

Accuracy of the Analysis

Since artificial stabilization forces are introduced intothe problem, users are advised always to check theaccuracy of results obtained with this technique. Thiscan be done in the following ways:

� Compare the stabilization energy to the potential energy. The stabilization energyshould be much less than the potential energy for an acceptable result.

� If the previous condition is not satisfied, theuser can further compare the stabilizationforces to the applied loads and reaction forces.An acceptable result requires that these forcesbe much smaller than the others. Such a casecan occur when an elastic system is loaded

first and then unloaded significantly, resulting ina small elemental potential energy but largestabilization energy.

� When the above conditions are not fulfilled, theresults still might be valid if a large part of anelastic structure undergoes rigid body motion,as in a snap-through simulation. But the resultshave to be used extra carefully.

Sample Problems

The nonlinear stabilization technique can be used in awide range of unstable problems. It is illustrated herein several examples (Figures 1 through 8) that couldnot have been solved otherwise in a practical mannerwith conventional FEA methods.

Collapsed Fuel Container

The model (Figures 1, 2 and 3) represents half of a five-liter fuel container modeled with SHELL181 elements with reduced integration as well as two pairsof contact elements defined on both the inside andoutside surfaces of the bottle. The material consideredis elastic, and applied boundary conditions and forcesare shown in Figure 1. The initial simulation withoutstabilization diverges at time 0.38 and no significantdeformation is visible, as can be seen in Figure 2. A restart analysis is performed from the substepbefore the last converged one with stabilization turnedon with the constant option and controlled by a damping factor of 1.5. Using stabilization, the analysiscan be carried out up to the point at which the bottle isalmost fully collapsed, as shown in Figure 3.

Figure 2. Final deformationat which ANSYS divergeswithout stabilization

Figure 3. Final deformation obtainedusing the new nonlinear stabilizationtool in ANSYS 11.0


Local Pipe Buckling

This model (Figures 4, 5 and 6) represents a thin-walled pipe modeled with SOLID186 elements that is subjected to a large, pure bending deformation. The material is chosen as elasto-plastic with aTB,BISO definition. The geometry of the model,boundary conditions and applied pressures are shownin Figure 4. The initial analysis is run without stabiliza-tion and diverges at time 0.75 due to the instabilities developed as a result of the local buckling of the pipe.As can be noted in Figure 5, this stage shows very little

deformation compared to the initial configuration, andbuckling is not yet initiated. Therefore, the analysis isrestarted at time 0.62 and stabilization is turned onwith the constant option, and a specified energy valueof 0.04 is used. The model is solved to completion.The final deformation obtained with stabilization isshown in Figure 6.

Wrinkled Thin Membrane

The choice of this example (Figures 7 and 8) to test theperformance of the stabilization feature was motivated

Figure 4. Pipe geometry and boundary conditions

Figure 5. Equivalent stress at the last converged substep without stabilization

Figure 6. Final equivalent stress obtained with stabilization

Sample Problem: Local Pipe Buckling

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Technology Update


Figure 7. Square thin-film membrane example geometry and loading

Figure 8. Out-of-plane deformations

by two reasons: the challenges that any finite elementsoftware faces when simulating the development ofthe out-of-plane deformations in thin-film membranesand the availability of experimental data for compari-son in published literature (Alexander Tessler, David W.Sleight and John T. Wang, “Nonlinear Shell Modelingof Thin Membranes with Emphasis on Structural Wrinkling,” 44th AIAA/ASME/ASCE/AHS/ASC Struc-tures, Structural Dynamics, and Materials Conference, Norfolk, Virginia, AIAA 2003-1931, April 7 – 10, 2003,pp. 11).

The model represents a square thin membrane(Mylar® polyester film) modeled with 100x100SHELL181 elements. The model is clamped along thebottom edge and subjected to an in-plane shear loading along the top edge, as shown in Figure 7.Because there is no mechanism that can initiate theout-of-plane, buckled deformation, a well-known procedure is used that consists of imposing pseudo-random imperfections at each node in the out-of-plane direction. The imperfection magnitudes aredependent on the membrane thickness and are verysmall so that they do not influence the final deformedconfiguration. The imperfections, material data andgeometry employed are the same as in the above referenced literature. Since the structural instabilitiesare initiated soon after the load application, the stabilization feature is activated from the beginningwith the constant option and an energy value of 0.5.

The out-of-plane deformations, as shown in Figure 8, were found in close agreement with resultsavailable in the literature in terms of number of wrinkles, their orientation and amplitudes.

Summary

The new nonlinear stabilization technique shows significant potential for use in solving many of today’sformidable tasks such as post-buckling and othershell, beam and solid structures with instabilities. Thenovel stabilization technique proves to be a very powerful tool with very few limitations, and it can beused together with nearly any other nonlinear solutiontechnique (except arc-length method). The addition ofnonlinear stabilization together with the recently introduced rezoning feature has greatly amplified thepower of ANSYS nonlinear capabilities. It has provenitself as an important step in the advancement of simulating complex engineering processes. �

Sample Problem: Wrinkled Thin Membrane 35

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Tech File

One day I found myself thinkingof the many types of engineeringproblems that you can solvewith ANSYS software, rangingfrom electromagnetics to heattransfer, from forced vibration to

harmonic analysis, and many more. All these have onecharacteristic in common: They are all physical phe-nomena found in nature. This isn’t surprising, sinceANSYS technology was developed to solve physicalproblems using the finite element method, which ithappens to do very well indeed. However, I started toconsider the possibility of using ANSYS for problemsthat fall outside these traditional applications. Arethere any problems for which finite element analysis(FEA) might be suitable that are not necessarily physical in nature?

I remembered that when I use ANSYS software to model something simple like a cantilever beam, itcalculates a deformed shape that describes a parabola: the most efficient, least complex shape thatresults from the system’s boundary conditions, orknown values. Given the values of the deflection andslope at one end and the deflection at the other,ANSYS calculates a path for the beam that matches

By John CrawfordConsulting Analyst

Generating Interpolated Datawith Beam and Shell ElementsConvenient macros provide a way for ANSYS software to help study nontraditional problems.

the classical equation of Y=A+BX+CX2, in whichA=B=0 and C=M/2EI (M=bending moment, E=elasticmodulus and I=area moment of inertia). Just as aparabola is the most efficient equation for describing asystem that has three known values bounding it,ANSYS calculates the shape that is the most efficientand minimizes the potential energy stored in the beam.

More Data Points and Higher OrdersUsing ANSYS software to calculate the path of theexponential curve described by a simple second-orderequation may seem a little like hitting a pin with asledgehammer, but it offers the potential to solve morecomplex problems. We could solve a second-orderpolynomial without any trouble using traditionalmeans, but it becomes increasingly difficult to solvefor the constants in a polynomial as data points areadded and the order of the equation increases.

Since finite element analysis offers an alternativeway to solve for the value of Y as a function of X forany number of given data points, I decided to write amacro (curve.mac) that generates a beam model thatpasses through a series of points and plots thedeformed shape. The example shown in Figure 1 haseight sets of values for Y at X=0, X=1 … X=7. ANSYStechnology calculates the minimum potential energysolution for this set of boundary conditions, which alsohappens to be the shape of the least complex curvethat passes through these points. This is the samecurve we would obtain if we could solve for a seventh-order polynomial equation.

It’s nice to be able to see the curve that passesthrough these points on the screen, but we often findthe equation of a curve because we want to know thevalue of Y for any value of X. The finite element modeldoesn’t present us with an equation for this curve, butwe can use the functions in /POST1 to calculate thevalue of the displacement Y and the slope DY/DX for

Figure 1. Generating a least-complex curve between sets of two-dimensional points

any given X coordinate. So I wrote a macro calledyfuncx.mac that does this. The accuracy of these values is dependent on the resolution of the mesh thatis used, but, for practical applications, it is quite easyto get an answer that is accurate enough for ourneeds. Using ANSYS software in this manner gives usthe ability to obtain Y and DY/DX for any locationalong any line for which we have boundary conditiondata, regardless of how complex the curved line might be.

Handling Two VariablesCalculating values as a function of one variable is useful, but it would be much better to be able to dothis for two variables. We often want to interpolatedata that is a function of two variables, such as temperatures spread across a surface as a function ofX and Y, or displacement at a specific location as afunction of two varying loads. It can be difficult (andsometimes impossible) to use classical methods toarrive at the equation that describes the surface thatpasses through several points. Could FEA help ussolve problems like this?

Building upon the idea of using ANSYS to calculate Y as a function of X, it’s a relatively simplematter to extend this to a second dimension and calculate Y as a function of both X and Z. I wrote amacro (bumps.mac) that generates a shell model for agiven set of Y values that are a function of X and Z.Hardpoints are defined as the XZ locations at which Yvalues are known, the area is meshed, displacements

are applied in the Y direction that correspond to theknown values of Y, and the model is solved and post-processed. Figure 2 shows the shape of the surfacethat passes through the eight XZ locations for which Yvalues in which data was given in the macro.

Extending the Reach of FEAUsing classical methods to solve for a surface thatpasses through eight points in space is not easilyaccomplished, but ANSYS software can do it veryeasily. Whether we have eight points or 800 pointsdoesn’t really matter; we still can use ANSYS to generate a surface that passes through all of thesepoints. Once the surface is generated, it’s a simplematter of using ANSYS post-processing capabilities toobtain the value of Y for any X and Z coordinates. I wrote a macro that automates the steps needed todo this (yfuncxz.mac).

It’s reasonable to assume that the range of nonphysical problems that can be solved by ANSYSsoftware is not limited to the two examples I haveshown. It’s very likely that there are other applicationsfor finite element analysis that reside outside the physical domains in which we usually operate. If you have used ANSYS to successfully solve a nontraditional problem, feel free to send me an emailat [email protected] and tell me about it.

The macros mentioned in this column can bedownloaded from the ANSYS Solutions Web site,www.ansyssolutions.com. �


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Figure 2. Shell elements showing given set of Y values as a function of X and Z points

Tips and Techniques

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ANSYS 11.0 software offers enhancements thatstreamline setup of fluid structure interaction (FSI)problems within the ANSYS Workbench environment.Outlined below are two simple examples, with thehope that readers will apply these techniques to realapplications of their own.

FSI simulations can be broadly categorized asone-way or two-way coupled. One of the most common applications of one-way FSI is the solution ofthermal–stress problems, in which significant thermalstresses in the solid are induced by thermal gradientsin the flow field. In many of these cases, the resultingdeformation of the solid is small, and the flow field isnot greatly affected.

In our example, we’ll pick up after the CFD heattransfer simulation is complete and the FEA problemhas been partially set up in ANSYS Simulation. Loadsfrom ANSYS CFX software can be applied to the FEAmodel, as illustrated in Figure 1:

� After inserting a new Steady State Thermalanalysis, select the desired face(s) of the model,right-click and select Insert, CFX Temperature.

� In the Details view, select CFX Surface, Importand select the desired CFX results file. If aresults file already exists in the project, it will bechosen automatically.

ANSYS Workbench MakesSimulating FSI EasierEnhancements in version 11.0 streamlinesetup of fluid structure interaction problems.

By Judd Kaiser, ANSYS CFXTechnical Solutions SpecialistANSYS, Inc.

� Select the CFX boundary region name that corresponds to the selected faces. This steprequires some care: It is important that a CFXboundary condition exists that corresponds tothe desired faces in the ANSYS Simulationenvironment.

To perform a one-way FSI thermal stress analysis,a steady-state thermal analysis is performed first (witha temperature load applied from ANSYS CFX), and the resulting temperature distribution is applied as a thermal condition for a static structural analysis. (See Figure 2.)

For cases in which the structure deforms so significantly that it affects the flow field, two-way FSI is needed. Industrial examples include aerodynamicflutter of wings, buffeting of car hoods, transient windloads on buildings and bridges, and biomedical flowsinvolving compliant blood vessels and valves. Forcases such as these, both ANSYS and ANSYS CFXsoftware must be run concurrently with loads transferred between solver iterations.

The process for setting up a two-way FSI case in the ANSYS Workbench 11.0 environment is summarized as follows:

� Define the FEA model in ANSYS Simulation.

Figure 1. Transferring loads one-way from ANSYS CFX toANSYS software

Figure 2. Thermal analysis with loads mapped from ANSYSCFX feeds a thermal condition for a static structural analysis.

Geometry courtesy CADFEM GmbH.

� Select the faces in which loads will be transferred between the CFD and FEA simulations, then right-click and insert a FluidSolid Interface in the same manner as youwould insert any other constraint or load. (See Figure 3.) An interface number and defaultname (FSIN#) is assigned to each interface to connect the fluid–solid interface in ANSYSCFX-Pre.

� When the FEA setup is complete, the FSI simulation is not executed from the ANSYSSimulation environment. Instead, select theSolution object in the Simulation tree and selectTools, Write ANSYS Input File.

In ANSYS CFX-Pre, there are four basic steps tocompleting the FSI problem setup:

� Double-click on Simulation Type in the Outlinetree. Under Basic Settings on the SimulationType tab, set External Solver Coupling toANSYS Multi-field and select the ANSYS inp filethat was written out from ANSYS Simulation.

� Typically, two-way FSI applications involvemesh deformation. Double-click on the relevantfluid domain in the Outline tree and, under General Options, set Mesh Deformation toRegions of Motion Specified.

� For each boundary condition, mesh deforma-tion options are set under the Boundary Detailstab. For the FSI interface boundary condition,set Mesh Motion Option to ANSYS Multi-field.


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� Finally, under the Solver branch of the Outlinetree, double-click on Solver Control. This iswhere detailed solver controls are set for theCFX solver as well as coupling controls forcommunication with the ANSYS Multi-fieldsolver. Under the External Coupling tab, detailssuch as the number of stagger iterations,solver execution order, coupling under-relaxation and coupling convergence target are set.

With both the FEA and CFD setup complete,write the CFX solver definition file. New in ANSYS software version 11.0, the CFX solver manager can be used to launch and monitor the coupled ANSYSCFX and ANSYS simulation. The Define Run windowreferences both the ANSYS CFX definition file and theANSYS input file. During the run, the text output fromboth solvers and graphical convergence monitors areavailable for review.

When the coupled solution is complete, both theCFD and FEA results can be simultaneously post-processed in ANSYS CFX-Post, as shown in Figure 4.The ability to load multiple results files, includingANSYS results, is new in 11.0. For transient results,the time step selector will automatically synchronizethe fluid and solid results to a common time value. Creation of transient animations, including the produc-tion of mpeg movie files, is straightforward. Also newin version 11.0, displacements can be magnified inCFX-Post to visually emphasize deformation. �

Figure 3. Inserting a fluid–solid interfacein Simulation

Figure 4. Post-processing of the coupled ANSYS CFX andANSYS solutions is performed in CFX-Post. Shown is a modelof a three-lobe valve for a biomedical application.

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In the 1991 movie CitySlickers, actor Billy Crys-tal’s character, Mitch Rob-bins, is a big-city ad sales-man having a mid-life crisis.For his birthday, he goes on

a dude-ranch holiday, driving cattle from New Mexicoto Colorado. On the cattle drive, grizzled, no-nonsensetrail boss Curly Washburn (played by Jack Palance)teaches Mitch how to be a cowboy. In the process,Curly tells Mitch about the value of ignoring life’s many distractions while focusing on what’s centrallyimportant. As Curly points out, if you stick to a singlepurpose, everything else falls into place. The trick is figuring out that “one thing” you should focus on, which is often right under our noses, yet we fail torecognize it.

Running CAE Activities as aLean BusinessToday’s competitive pressures require companies to developmetrics, quality standards and operational models in leveragingthe full power of simulation as an integral part of product development processes.

By Mark Zebrowski,CAE ConsultantU.S.A.

Searching for Central Focus

For many companies, identifying what’s centrallyimportant for computer-aided engineering (CAE) intheir operations has been elusive. As a tool for functional performance evaluation, the technology hasbeen used in the engineering community since the mid-1970s and has experienced exceptionallyrapid growth during the last decade. Its effectivenessas a tool to replace physical testing varies widely from company to company and across various functional attributes.

As with many computer-based approaches,some companies are not sufficiently confident in CAEto move from the current levels of physical testing tomore of a predictive simulation-driven environment inwhich the technology is used as the principle methodto prove-out designs in the upcoming fully digitalworld. Instead, CAE often is relegated to the sidelinesof product development as companies wait in anticipation for software providers to come up withthat “one thing” in terms of features and functions thatwill show them the way to improved quality, reducedcost structures and quicker time-to-market for innovative products.

Guest Commentary

Stuck in a Time Warp

This narrow view, focusing on tactical elements only, has its roots in the early days of CAE, when companies were concerned about details such as element formulations, mesh generation speeds andcompute power. That’s what we all focused on backthen. Discussions at conferences centered on whohad the best isoparametric technology, the fastestCPUs and other technology-related topics of endlessdebate. Some remain stuck in this time warp, stillsearching for newer and better technology whenexperience has shown that tactical solutions alone won’t solve a company’s strategic and operational problems.

Significant changes in CAE implementation comeabout when you begin to broaden your view in consid-ering what’s really important for CAE: the overridingstrategy of establishing optimal simulation processesand integrating them into the overall product develop-ment process. Such a self assessment shows that the“one thing” companies must focus on in leveragingthe full power of CAE is a shift in thinking in treatingCAE not just as a technology but as a robust, repeti-tive and consistent business process in which theproduct is a cost-effective stream of superior, high-quality and timely designs. In this broader view, therole of CAE is elevated to that of a general engineeringtool, not just one to be used exclusively by “crafts-persons” and dedicated analysts.

Overriding Strategies

Running CAE as a business has a variety of character-istics common with most business operations:

� A business model having measured inputs andoutputs, with a known return on investment(ROI)

� A business plan with an evaluation of the present and future business conditions, including a technical and operational plan forsustaining and growing the business

� Well-defined series of processes, with supporting documentation, with process flexibility when allowed as well as rigidity when required

� Metrics keyed to the final product — the accurate prediction of functional performance

� A quality operating system (QOS) to guideenhancements and improvements

� An operational model that looks beyonddetailed CAE tasks (getting data, building amath model, post-processing, etc.) toward the more important process steps in the engineering prediction process

� Evaluation systems that include various qualityelements and do not solely emphasize cost or speed

If organizations begin to view their virtual prototyping/CAE activities as a business operation, theywill realize that they absolutely need a set of principles and operations that will help expand its scope of activities over time, increase its level of funding within the company, continuously improve theservices it provides to those relying on simulation resultsand provide an ever-increasing ROI to the parent organization. All this directly relates to issues that anysuccessful business must address: growth, marketshare, customer satisfaction, budgeting and profitability.

Focusing on a Business Model

The next step is to ask “What business do I choose for amodel?” For me, the answer was right under my nose. I was privileged to work for a company that was, forabout 20 years, a recognized leader in CAE. One of myassignments was to lead a group of about 40 technicalleaders in a study of what improvements would allowCAE to lead design. One of the books recommended to me was The Machine that Changed the World (by Womack, Jones and Roos) discussing how craft pro-duction processes were replaced by mass productionand then by lean production.

So for CAE, the “one thing” for us became this:Run it like a business, a lean business. As a growthstrategy, lean CAE supports fast-to-market productplanning, allowing development of emerging marketsegments. It becomes the first choice for experimenta-tion, development, target cascading, validation and final verification of designs due to higher confidence in itspredictive capability and its expanding scope of appli-cation. Finally, it is continuously improved by dedicatedpersonnel driven by both business and accuracy metrics. Running CAE as a lean business in this mannerleverages the full power of simulation as an integral part of product development processes and as a competitive advantage to companies adopting this strategy. �

Mark Zebrowski ([email protected]) spent 32 years

working on various CAE, NVH and vehicle attribute programs

at Ford Motor Company and was a technical manager for

12 years prior to his retirement in 2005. Currently, he is

an independent consultant specializing in the business

justification of CAE and integration of analysis into efficient

product development processes.


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Ansys Solutions 05 2006

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