Fully Automatic In-cylinder Workflow Using HEEDS / es-ice...
Transcript of Fully Automatic In-cylinder Workflow Using HEEDS / es-ice...
Fully Automatic In-cylinder Workflow UsingHEEDS / es-ice / STAR-CD
Simon Fischer – Senior ICE Application Support Engineer – CD-adapco Nuremberg Office
Gerald Schmidt – Director/Powertrain - CD-adapco New York Office
Introduction and Enabling Technology
Workflow and HEEDS Portal Description– Underlying Scripts
– Data Preparation
– CAD Modification
– Surface Preparation
– Automatic Meshing
– Physical / Numerical Model Setup
– Running STAR-CD
– Postprocessing
Demo Study: The Optimized Race Engine
Further Examples of Successful In-Cylinder and Related Studies
Outline
HEEDS is a well established MDX tool applicable to many CFD problems– Red Cedar Technology recently developed dedicated HEEDS portals
for pro-STAR, es-ice, and STAR-CD making it easier to define workflows for in-cylinder simulation
The key enablers of MDX for in-cylinder simulation are robust moving mesh technology and high fidelity physics capability– A major focus of es-ice development has been to provide a fully
automated robust meshing technology with minimum user intervention
– STAR-CD provides a big library of state-of the art in-cylinder relevant physics models (from multi-phase to combustion chemistry)
This presentation shows the possibility of in-cylinder simulation using a fully automatic HEEDS/es-ice/STAR-CD workflow
Introduction and Enabling Technology
Generic scripted process of STAR-CCM+ surface preparation, es-ice fully automatic meshing and model setup, pro-STAR model setup, STAR-CD cluster submit, and es-ice/pro-STAR postprocessing
Minimum User Interaction to Prepare Input Data
Process, parameter setting/variation, io-operations, postprocessing managed by HEEDS MDO employing the STAR-CCM+ portal and recent STAR-CD, es-ice, and pro-STAR portals
Meshing and physics parameters and results output managed through HEEDS parameter tagging
Workflow Description
Generic scripted process of STAR-CCM+ surface preparation, es-ice fully automatic meshing and model setup, pro-STAR model setup, STAR-CD cluster submit, and es-ice/pro-STAR postprocessing
Workflow Description: Underlying Scripts
Minimum User Interaction to Prepare Input Data– Surface preparation in STAR-CCM+ (GeometryPreparation.sim)(Geometry from CAD-Modeller, Imported CAD, Discretized Surface)– Naming convention– Orientation, Scaling, Valve and Piston position– CAD/surface repair (clean CAD, waterproof surface)
Deliver Boundary Conditions in appropriately formatted files
Workflow Description: Data Preparation
Process, parameter setting/variation, io-operations, postprocessing managed by HEEDS MDO employing the STAR-CCM+ portal and recent STAR-CD, es-ice, and pro-STAR portals
Meshing and physics parameters and results output managed through HEEDS parameter tagging
Workflow Description: HEEDS Process
Workflow Details: CAD Modification
Optional:Direct CAD Design Parameter (if exposed)access through HEEDS‘sdedicated Portals:• here STAR-CCM+ Portal• Also available:
NX, CATIA, CREO,...
ParametrizedSTAR-CCM+ Geometry Preparation sim-File
Workflow Details: Surface Preparation
• Input STAR-CCM+ Geometry Preparation sim-File• Automated Parts Based STAR-CCM+Surface Remesh using es-ice best practices • (Optional) Automated Additional Static Part Volume Meshing• Export of es-ice -appropriate .dbs Surface fileand additional ccm volume meshes
• Underlying meshing script featuring latest es-ice automatic meshing technology and best practice
• User input is limited to a minimum of mesh parameters, e.g. mesh base size, prism layer thickness, etc.
• No expert knowledge of es-ice template mesh generation is necessary
• Yet scripted meshing is open source and fully customizable for expert users
Workflow Details: Automatic Meshing
Workflow Details: Automatic Meshing
es-ice scripted meshing HEEDS portal to automatically
• Script allowing for Automatic Parameter Tagging to expose parameters to a HEEDS design study (e.g. Make a mesh study)
tag parameters
e.g. Make a mesh study
Workflow Details: Automatic Meshing
High quality moving mesh with NO user intervention
Workflow Details: es-ice Model Setup
es-ice scripted model setup• Boundary conditions• Initial conditions• Predefined best practice
setup scripts • Cold flow• Mixture preparation• Combustion study
• All scripts open source and fully customizable
• All scripts allowing for Automatic Parameter Tagging to expose parameters to a HEEDS design study
Workflow Details: pro-STAR Model Setup
pro-STAR scripted model setup• Liquid phase setup for
injector boundary conditions, liquid film, and spray physics
• Predefined best practice setup scripts • Cold flow• Mixture preparation• Combustion study
• All scripts open source and fully customizable
• All scripts allowing for Automatic Parameter Tagging to expose parameters to a HEEDS design study
Workflow Details: Running STAR-CD
Scripted cluster submit including all file handling (copying forth and back), monitoring jobs, etc., handling multiple computational resources
Workflow Details: Postprocessing
es-ice postprocessing plugin HEEDS portal to automatically tag results
Automatic Parameter Tagging to expose Results to HEEDS
Enablingpostprocessing in HEEDS for an MDX study
Workflow Details: Postprocessing
• Scripted call of pro-STAR engine animation script
Workflow Details: Postprocessing
Fully embedded postprocessing in HEEDS
Workflow Details: Project Management
Fully integrated management of • Processes (Cold Flow,
MixturePreparation, Combustion)
and related • Design Exploration Studies (e.g.
Single Baseline, Mesh Sensitivity, Geometry Optimization, ...)
within the HEEDS Environment
The sample study features:
Automatic CAD modification through STAR-CCM+ CAD modeler
Automatic generation of moving mesh for intake and compression stroke for each design using es-ice
Lagrangian spray, wall impingement, liquid film
Tracking of fresh air, fuel, and residual through active species
Turbulent flow field assessment with STAR-CD
Evaluation of engine data
Optimization of design through HEEDS
Users touch neither the es-ice nor the pro-STAR GUI, leaving required expertise to a minimum
Demo Study: An Optimized Race Engine
Design parameters: Piston bowl shape and injector direction
Goal: Maximize fuel and maximize turbulence at the ignition point
Demo Study: An Optimized Race Engine
Demo Study: Results
All engine relevant postprocessing through HEEDS UI
Demo Study: Sample Results
BaselineBest Design
Demo Study: Performance
Model size: ~ 1 mio cells @ BDC (1 mm base size), time span 380 degrees crank angle (intake and compression stroke)
Total turnaround time per design: ~ 3 hours– Preprocessing, meshing, and postprocessing on 1 CPU: ~ 25
min
– Run on 48 CPUs: ~2.5 h
Parallel design assessment through HEEDS– Here 4 designs in parallel
~ 45 min per design occupying 192 CPUs
– 100 designs evaluated in 83 hrs
License requirements:– 2 es-ice pre/post
– 4 es-ice run
– 164 HPC STAR-CD
– 4 enablestar
– 5 STAR-CCM+
– 1 HEEDS
Transient port flow optimization (Pre-Sales demo–confidential)– Maximize tumble and trapped mass through port design optimization– Fully transient: 300 designs in 2 days on 64 cores
Diesel piston bowl shape optimization (JLR – customer presentation)– Presented at last year‘s European ICE Workshop in Maranello
Prechamber gas engine workflow (Support demo for Caterpillar)Gasoline spray calibration in a bomb experiment (Internal training) – Calibrate spray break-up model to match experimental properties
Automatic testing of es-ice automatic meshing performance (Internal)– Extraction of best practices and sensitivity study on meshing parameters
for optimum mesh quality
Evaluation of DARS combustion libraries in STAR-CD box model (Internal)– Tool to explore combustion libraries for auto-ignition and laminar flame
speed in CFD operating mode, valuable for library validation
Turbulent Jet Ignition (TJI) combustion model validation and best practice study (Internal)– Combustion model assessment and calibration
Examples of Successful In-Cylinder and Related Studies Using HEEDS/es-ice/STAR-CD
The Application of HEEDS MDO to the Optimization of Diesel Piston Bowl Design,
Paul Dunkley, Jaguar Land Rover
(Presented in Maranello at the European ICE Workshop 2015)
Paul D. of JLR stated that he can justify the investment in HEEDS purely because of cost savings due to process automation, even before running one single MDX study. Due to the advancements in es-ice automation transient full cycle es-ice/STAR-CD in-cylinder MDX is now possible!
Piston Bowl Optimization Demo (Internal)
SOOT NO
Prechamber gas engine workflow
(Support demo for Caterpillar)
• Challenge • Calibrate fuel spray of gasoline multi-hole injector
for a STAR-CD in-cylinder analysis by using a static spray chamber
• 4 Calibration parameters as design variables• Initial droplet PDF “Rosin-Rammler” X & Q
• Spray cone angle and nozzle diameter
• 2 Calibration objectives • Spray penetration length as function of time
• Droplet size distribution 60mm downstream
• Automated calibration process
• 15 min per case 8-10 hours total
• Impact by HEEDS• Curve fitting of two calibration objectives
• Manpower time savings automatic process does not require manual interaction
STAR-CD Spray Model Parameters
Curve Fitting by HEEDS
Final Spray Calibration
Gasoline spray calibration in a bomb experiment
(Internal training)
Automatic testing of es-ice automatic meshing performance
(Internal)– Test of meshing technology, extraction of meshing best practices, and
sensitivity study on meshing parameters for optimum mesh quality
Evaluation of DARS combustion libraries in STAR-CD box model (Internal)
– Tool to explore combustion libraries for Auto-Ignition and Laminar Flame Speed in CFD operating mode, valuable internal validation tool
Turbulent Jet Ignition (TJI) Combustion model validation and best practice study (Internal, ongoing)
Generic scripts for standard engine studies (meshing,
combustion, mixture preparation, etc.) will be delivered in a
consistent and version numbered manner together with STAR-
CD/es-ice installation
Maintenance, bug fixing, and enhancement of these scripts will
be managed (e.g. through GIT)
What Might Be Next?
HEEDS Portals have been delivered for es-ice/pro-STAR/STAR-
CD in the latest HEEDS release
The new portals enable automated workflows and design
exploration to be performed for in-cylinder transient
simulations in a convenient, easy, and consistent manner
The provided scripts allow for easy start up for new users
leaving full flexibility to advanced users and custom studies
Users touch neither the es-ice nor the pro-STAR GUI, leaving
required expertise to a minimum
Summary
Thank you for your attention