Modeling, Structural & CFD Analysis and Optimization of UAV

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Transcript of Modeling, Structural & CFD Analysis and Optimization of UAV

  • Modeling, Structural & CFD Analysis and Optimization of UAV

    Dr Lazaros Tsioraklidis

    Department of Unified Engineering

    InterFEA Engineering, Tantalou 7 Thessaloniki GREECE

  • Next Generation tools for UAVs

    The current paper present the usages of Hyperworks on the design of New ages Aerostructures as UAV's.

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  • UAV marketplace a moving target

    UAVs are now in service in more than 50 countries.

    During 2007, these aircraft logged more than 500,000 flight hours, increase by logarithmic rate.

    Thousands of different aircraft in various stages of design, development or production.

    70 active companies and nearly 200 unique platforms enter production or currently under development.

    Top 30 programs accounted for ~3,000 aircraft deliveries during 2008 and will deliver 3,350 more during 2009 about 93 percent of the delivery total. Over the next five years, the same programs will deliver about 13,000 aircraft. Over our 2009-2018 forecast period, they will account for close to 65 percent of expected UAV deliveries.

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  • UAVs Future

    Teal Group's 2010 market study estimates that UAV spending will more than double over the next decade from current worldwide UAV expenditures of $4.9 billion annually to $11.5 billion, totaling just over $80 billion in the next ten years.

    A new study reflects the rapid growth of interest in the UAV business by increasing the number of companies covered to almost 30 U.S., European and Israeli companies, and reflect the fundamental reshaping of the industrial environment

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  • Types of UAVs

    Target drones UAVs that simulate enemy missiles or aircraft in the demonstration and testing of antiaircraft and antiship missiles systems. Radar decoys Unmanned decoy aircraft deployed from a larger manned aircraft and designed to subvert, confuse or fool enemy radar systems. Information, surveillance and reconnaissance (ISR) aircraft UAVs that perform a variety of surveillance, observation and data-relay missions. For combat troops on the ground, small UAVs, including micro-UAVs (handheld/hand launched), provide over-the-hill scouting, to avoid ambushes and scare off insurgents. Unmanned combat aerial vehicles (UCAVs) Aircraft designed to provide unmanned weapons capabilities and support manned aircraft. Their capabilities include the use of bombs and missiles, electronic warfare equipment and directed-energy weapons.

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  • Hyperworks A platform for Innovation

    Altair Hyperworks is an engineering simulation environment which can use from engineers during all stages of the Design and Optimization of UAV's. From design stage when the engineer tests and validates new Shapes and mechanism and determine correct shapes for the engine inlet, determines optimum composite structure, reduce weight and provide more Payload.

    Modern FE Modeling

    Robust CFD solver

    Motion Dynamic

    PA speed up projects

    linear and non-linear simulations

    Ultimate post processing

    Explore, Study, Optimize

    Reduce weight

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  • CFD Analysis & Optimization on UAV

    From Design to the Reality of Flow Challenges Low Drag Cd High lift CL Less Noise Eliminate Turbulence

    First 3D Design

    Modeling for CFD

    Shapes for Optimization

    Coupling CFD +

    Optimization code

    Post Processing

    Determination of pressure distribution on the surface of the UAV that later on leads to calculations of aerodynamics characteristics of uav such as CL, CD and CM at various angle of attack Visualization of the airflow around the UAV using Post Processing to recognize some critical area with possible vortex reduction in the near future. The analytical of aerodynamics characteristics for various angles of attacks using CFD simulation will be conducted in this final stage

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  • High Quality meshing for CFD

    By using Hypermesh the total cost on human hours from Geometry cleanup to tetra mesh reduced by 60%. Special tools as Layer meshing & Refinement box option provides fast and accurate mesh for CFD analysis.

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  • CFD Optimization of the Wing shape

    The NACA 4412 Airfoil choose as an option for the UAVs wing, the NACA 4412 profile provides high CL on low speed for subsonic aircrafts. Several shapes (50) created for the optimization of the wing for reducing the CD and increase CL, in the same time several constrains have to be satisfied as volume and turbulence.

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  • Optimized wing

    The optimization of the wing create optimize performance as : Cd reduction = 35% CL increased =5% Turbulence reduction = 21%

    Initial

    Optimized Cd /Iteration

    Cd

    Iterations

    Optimized

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  • Optimized wing on several angles of attack

    For each wind tunnel airspeed, the value of CL increases as the angle of attack is increased until its maximum value at around = 35 and decreases afterwards with lower slope. Computational Fluid Dynamics (CFD) results at Mach 0.6 and 0.8 also give the same trend with maximum CL located at = 39 and = 35 respectively. It is observed that the value of CLmax increases as the air velocity of the wind tunnel is increased. Hence, the CL max increases with the increase of Reynolds number. This explains the difference of values of CL max between the experiments and the CFD.

    Drag Coefficient Analysis

    Lift Coefficient Analysis

    The variation of drag coefficient (CD) versus angle of attack () taken at different air speeds and Mach numbers. It is observed that the variation of drag coefficient is very slow and almost constant at low angle of attacks (below 8). In that range of , CD is small, below 0.03 for both experiments and CFD. As explained in the previous section, at low angle of attack, the air flow is still attached to the body and the wing. Above 8, CD grows at higher rate as is increased. Within this range, the wing is already in stall condition. Around 35, a slight deflection occurs on wind tunnel experiment curves. This is where the lift coefficient reaches its maximum value. This deflection is not clearly seen on the CFD curves. Beyond this angle of attack, the drag coefficient continues to increase with almost the same slope as between 8 and 34, and it is getting slower when approaches 90. From the overall curves, it is observed that higher airspeeds (or higher Reynolds number) produce higher drag coefficients.

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  • Nose Optimization

    The optimization of the Nose create optimize performance as : Cd reduction = 18% CL increased =2% Turbulence reduction = 10%

    Morph volume & Shapes

    Initial

    Optimized

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  • Engine inlet Optimization

    The optimization of the Engine Inlet create optimize performance as : Cd reduction = 10% CL increased =2.89% Turbulence reduction = 12%

    Morph volume & Shapes

    Initial

    Optimized

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  • Conclusions of the CFD & Structural Optimization

    CFD Optimization Conclusions CFD Analysis & Optimization Cd Reduction : 51 % CL Increased : 9.89 %

    Optimized Turbulence flow

    Optimized Inlet for Better Engine Performance

    Cd = Fuel Consumption Reduction

    CL = Optimized Flight Load

    Stabilization Problems Solved

    Combat Radius Increased

    34%

    Max take off load increased

    10 %

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  • Structural Analysis and Optimization

    Load transfer from Acusolve to Hypermesh for Linear Analysis and Optimization

    Data from: Angles of Attack 00, 50, 150, 200

    Aerodynamic loads on the wing from extra external fuel tanks External Devices as cameras etc

    Linear

    Interpolation

    Pressure on the UAV surface Structural model of the UAV

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  • Structural Analysis of the UAV wing

    Analysis 25 Loadcases (strength, pressure) 370.000 Elements 15 Material types 842 Plies 145 Laminates

    Aerodynamic Pressure on the wing surface

    Composite Structure

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  • Deformation of the wing at angle of attack 00 Stresses on the wing at angle of attack 00

    Structural Analysis of the UAV wing

    The UAV Wing is made by CFRP Material, several parts