Kestrel A CREATE Aircraft Simulation Tool

Transcription

1 Kestrel A CREATE Aircraft Simulation Tool AFOSR Test and Evaluation Research Opportunities Workshop July 2012 Dr Scott A. Morton, Kestrel Principal Software Developer April 2012

2 CREATE-AV Product: Kestrel Kestrel Key Requirements Solve major aircraft program issues (flight mechanics anomalies, fluid-structure interactions, airframepropulsion integration, flight controls integration, store separation) Solve aircraft problems with jet and propeller propulsion, at low speed, transonic speeds, and supersonic speeds, dropping stores or cargo, in formation with other aircraft or landing on a carrier Easy to use, scalable on new architectures, fast turn around (hours for a full aircraft), economical to maintain and evolve Page-2

3 Kestrel Architecture Unique Event Driven Infrastructure Allows significant growth in Use Cases with no modifications to the source Developed specifically for CREATE-AV resulting in a low overhead (1 to 3%) independent of core/processor count All APIs and data structures for components consistent across CREATE-AV products Kestrel, Helios, and Firebolt share components for reduced development cost Only about 2000 lines of code with unit/integration/system overnight testing User Interface for job setup, mesh manipulation, post-processing, and pre-flight Page-3

4 Kestrel v2.0 Capabilities Static Rigid Aircraft Rigid Single Body Prescribed Motion Aeroelastic Aircraft using a modal structural solver Control Surface Motion 6-DoF Predictive Motion Prescribed Aircraft with Control Surface Motion 6DoF Aircraft Motion with Control Surface Motion Prescribed Aeroelastic Aircraft Motion 6DoF Aeroelastic Aircraft Motion Status: v2.0 is available to users at the DSRC s and on some of the user organizations closet clusters Page-4

5 Kestrel v3.0 Capabilities All v2.0 Single Mesh Capabilities using multi-mesh on a Background Mesh Static Rigid Aircraft with Prescribed Store Relative Motion Static Rigid Aircraft with 6DoF Store Relative Motion Static Rigid Aircraft with Prescribed or 6DoF Motion Store with Prescribed Moving Control Surfaces Time Varying Propulsion Effects (Firebolt Team) Note: v3.0 Planned Release is 3 rd Quarter FY12 Page-5

6 Kestrel v4 Capabilities v4.0 Capabilities/Attributes Internal Infrastructure changed to be a CREATE-AV wide infrastructure used by Kestrel, Helios, and Firebolt Near Body-Off Body (NBOB) solver paradigm introduced to improve off body accuracy and flow phenomena tracking Native Near Body Unstructured Flow Solver introduced Potential Impact on the DoD All s/w native with unit/integration/system regression testing NBOB paradigm allows tracking of vortices much farther downstream to determine aerodynamic impact on empennage, aircraft in close proximity with other aircraft, ground, or carrier decks, and cargo/store separation Note: v4.0 Planned Release is 2 nd Quarter FY13 Page-6

7 Kestrel v5 Capabilities v5.0 Capabilities/Attributes Finite Element Solver introduced to allow FSI tight coupling with high fidelity structural model (previously only modal analysis) Automatic Flight Control System component added for closed loop control Major improvements in UI for Case Management, Pre- Post Processing, Connectivity to DSRC s Potential Impact on the DoD High fidelity structures coupled with nonlinear aerodynamics necessary to simulate structural freeplay and other difficult FSI phenomena Design and check out inner loop control laws with high fidelity aerodynamics Ease of use improvements can tailor the software to DoD acquisition processes increasing efficiency Note: v5.0 Planned Release is 2 nd Quarter FY14 Page-7

8 Vision for CREATE-AV Use in Conceptual/Preliminary Design Design Analysis After Paring Down to ~10 Design Concepts Detailed Performance Assessment for the Whole Envelope at High Fidelity Against the RFP Detailed Engine Design Start with rigid a/c model Aero Analysis Preliminary Control Surface Sizing Preliminary Structural Layup Control System Development Detailed Structural Layup Preliminary Performance Compared to the RFP Acceptable Yes/No? Add control surfaces, structures, propulsion to a/c model Page-8

9 Game Changing Combination High Performance Computing High Fidelity CSE Code System level high fidelity solver including aerodynamics, structural dynamics, flight mechanics, and propulsion Efficient on large processor count (single simulation in hours, full envelope in days) Single Executable Of Modules CFD Fluid-Structure Structural Rigid-Grid Solver Interface Solver Move Mesh Adaptation Mesh Deformer Integrated Force & Moment Calculator Infrastructure Engine Thrust Aircraft On-the-Fly Trim Autopilot 6DOF Model Visualizer Store-Release Prescribed Control Surface Constraints Motion Deflection Additional Executables CFD Solver Autopilot System Identification High Performance Computing Large computational resources (order 10 4 to 10 5 cores) Current US DoD buys are for several machines at approximately 100,000 cores Compact Model Building Approach that can convert days of high fidelity CSE to compact, efficient model for use on laptop/workstation Approach that can allow higher and higher fidelity simulation (add control surfaces, aeroelasticity, propulsion, etc.) OSR/PA-Clearance Page-9

10 Multi-axis Training Maneuver Pitch-Yaw Chirp Composite Pitch-Yaw Chirp maneuver allows a single motion input to create a model including motion about two axes a = deg, b = 0+15 deg Input signals made orthogonal (dot product = 0) Requires full span F-16C grid Conditions: M=0.6, Alt.=5k ft. Page-10

11 System ID Applied to Multi-axis Training Maneuver: Pitch-Yaw Chirp SIDPAC Model: C L 7 13 ( a, b, p, q, r) C 2 C bp C a q C r C C 8 2 b p C b q C C a C q C p Validated against static C L -a data and single axis motion pitch chirp ab C a C p C 2 b C aq 12 5 pr 2 C bpq 6 Page-11

12 2.5g Wind Up Turn Flight Test Maneuver Prescribed motion based on flight test data (rotations only) Use reduced order loads model to perform maneuver & compare Good Lift prediction Drag prediction not as good as expected Conditions: M=0.6, Alt.=5k ft. Lift Drag Page-12

13 Training Maneuvers in 6-DoF Incorporate both translation and rotation into the training maneuver to provide better regressor space coverage Much better drag model predictions resulted C D Page-13

14 1 Out_Array RELEASE_TIME Release Time OutArray OutArray ALPHAS Q (deg/sec) BETAS R (deg/sec) PHII P (deg/sec) TIME (TOF) MSTORE 0 Clock alpha_s Q (deg/sec) beta_s R (deg/sec) phi P (deg/sec) TIME (TOF) Clock Release Time mach tof 1 Sensors & Cmds MATLAB Function Controls Vector Controls Vector mach1 alpha_cmd alpha q1 beta_cmd beta r1 phi_cmd phi1 p1 Mach_interpolate_coeff Terminator NAVSEP Kernel mach Autopilot alpha_cmd alpha_ebt q_ebt beta_cmd beta_ebt r_ebt phi_cmd phi_ebt p_ebt tof HSAD AP Out_Array Out_Array alpha mach1 delta_p_cmd delta_y _CMD delta_r_cmd Memory sim_out To Workspace alpha mach d_f in_p d_f in_y d_f in_r Coeff LUT DPitch Coef f s DYaw Coef f s DRoll Coef f s 1 SURF01 command 1 SURF02 command 1 SURF03 command 0 SURF04 command [ ] SURF04 Coeffs 0 SURF05 command [ ] SURF05 Coeffs SURF01 SURF02 SURF03 1 Controls Vector SURF04 SURF05 Ultimate Goal Integrate all modules into high-fidelity tool capable of developing accurate models of full elastic aircraft configurations Fluid-Structure Interpolation Control Surface Deformation Fluid Grid Deformation Structural Model Loads = f (q, M,a,a 2,q,aq,q 2, ) Aerodynamic Loads Autopilot Integration Engine Thrust Model System ID Page-14

15 Code Capability & Attributes Kestrel Roadmap Solutions Analysis New Attributes A B C D Technology Development 3 Case Management Adjoints for Design Optimization Modular Swappable Components Dynamic Surface Loads ROM Lightweight CREATE-AV Infrastructure Customer Module Plug In Unit/Integration/System Overnight Testing 1/10 Solution Turn around Time 2 All Native Components 10x Parallel Scalability Increase Easy to Use User Interface Near Body Strand Solver 3D Vis in UI New Capability Near Body Adaptive Mesh Refinement On the fly Vis Aeroelastic A/C 1 Store/Cargo Release Near Body Load Balancing New Machine Arch s Control Surfaces Time Varying Propulsion Near Body Load Balancing 6DoF Single Body Finite Element Structures Maneuvering Aeroelastic A/C NB High Order Aero Aeroelastic Wing Autopilot Flight Multiple Body 6DoF Tracking Refueling Flight Coupled Full Annulus Engines Maneuvering Rigid A/C Maneuvering Store Separation Gust Response Flight Missile Plume Inlet Ingestion Subsonic, Transonic, Supersonic Aerodynamics Trimmed Flight Carrier Deck Helo/FW A/C Landings Engineering Development Product Deployment Operations and Support Page-15

16 Kestrel End-State Timeliness Decision Data Overnight - Aircraft maneuvering simulation in hours, full aircraft flight envelope in a day Design Space Model Overnight Compact design space models based on high fidelity physics available for use in component design or pilot in the loop simulations Accuracy Realistic Aircraft Simulate cargo, fighter, manned, unmanned aircraft at subsonic, transonic, and supersonic speeds in operational conditions Affects Acquisition at the Costliest Stage Hi-fi tool integrated into the conceptual and preliminary design processes (e.g. DaVinci) to eliminate late discovery of defects Warfighter Payoff More Capable Aircraft/Weapon Systems High fidelity multi-disciplinary simulations translate to less conservative flight manuals Safer Flight Systems High fidelity multi-disciplinary simulations mean fewer surprises in flight test/missions More Aircraft on the Ramp Using high fidelity multi-disciplinary analysis during conceptual and preliminary design eliminates costly rework in EMD Page-16