Numerical simulation of maneuvering combat aircraft

Transcription

1 Numerical simulation of maneuvering combat aircraft Andreas Schütte DLR - German Aerospace Center Institute of Aerodynamics and Flow Technology Oct. 14 th 2005, Stuttgart Folie 1 > HLRS 2005 > A. Schütte

2 Numerical simulation of maneuvering combat aircraft Gunnar Einarsson, Britta Schöning, Axel Raichle, Wulf Mönnich, Thomas Alrutz, Jens Neumann, Jörg Heinecke DLR - German Aerospace Center Institute of Aerodynamics and Flow Technology Oct. 14 th 2005, Stuttgart Folie 2 > HLRS 2005 > A. Schütte

3 Overview Motivation Objectives Simulation Environment Experimental Simulation Numerical Results HPC Requirements and Resources Summary and Outlook Folie 3 > HLRS 2005 > A. Schütte

4 HPC Requirements Institut of Aerodynamics and Flow Technology Braunschweig /Göttingen Folie 4 > HLRS 2005 > A. Schütte

5 Motivation Source: Cenaero Folie 5 > HLRS 2005 > A. Schütte

6 Objectives of the DLR Project SikMa Prediction of the unsteady behavior of maneuvering aircraft. Development of a numerical simulation environment for calculating maneuvers of a free flying elastic combat aircraft. Realized a by multi disciplinary time-accurate coupling of CFD, Structure Dynamics and Flight Mechanics within the framework TENT. SikMa is a multidisciplinary project were several DLR Institutes are involved: Institute of Aerodynamics and Flow Technology Institute of Aeroelasticity Institute of Flight Systems DLR Sistec Folie 6 > HLRS 2005 > A. Schütte

7 Simulation Environment TENT Codes are implemented in TENT via wrappers. TENT carries out data transfers and communication between codes. TENT can distribute applications over different platforms SimBrowser: Definition of grid hierarchies for CHIMERA grids definition of all movements of parts and grids relative to each other animation and test of movements creation of motion and hierarchy files for the CFD- Code-TAU Folie 7 > HLRS 2005 > A. Schütte

8 DLR TAU-Code CFD-Code solution of RANS equations for arbitrarily moving bodies on unstructured meshes hybrid meshes (hex., prisms, tetra., pyram.) FV using dual grid approach, MG accelerated unsteady via dual time stepping state-of-the-art turbulence models grid adaptation (refinement & derefinement) CHIMERA technique deforming mesh capability designed for massively parallel computers validated for a large number of test cases Folie 8 > HLRS 2005 > A. Schütte

9 DLR TAU-Code Chimera approach Chimera boundary of the flap Chimera boundary of the wing Realized soon: Automatic hole-cutting approach Folie 9 > HLRS 2005 > A. Schütte

10 DLR TAU-Code Mesh adaptation (unsteady calc.) Stream lines & Total pressure distribution History of mesh adaptation Folie 10 > HLRS 2005 > A. Schütte

11 SIMULA Flight mechanics library Simulation environment SIMULA delivers the solutions of the flight mechanics equations Trimming calculation Analyze stability Maneuver simulations with 6 DoF and control devices Coupling of Aerodynamics/Flight mechanics Implicit time integration scheme Close coupling within each pseudo time-step Implemented models for SikMa Rolling delta-wing with trailing-edge flaps Generic 6-DoF model (e.g. X-31) Folie 11 > HLRS 2005 > A. Schütte

12 CSM-Code Structural mechanics simulation Two approaches Discrete approach: Coupling with the overall FE-Model Modal approach: Coupling with characteristic Eigenmodes Characteristics Coupling Aerodynamics/Structure: Loose/weak coupling scheme coupling within each physical time step Solving the CSM-equations: Implicit Newmark integration-scheme Spatial coupling: Scattered data interpolation methods for force and deformation transfer Coupling in time: Conventional Serial Staggered-algorithm with predictor- /corrector step for the CSM calculation Determination of the system matrices: Reduced system matrices MAA and KAA imported from NASTRAN Folie 12 > HLRS 2005 > A. Schütte

13 Experimental Simulation Wind tunnel experiments Objectives Generating a validation data base for the numerical simulation. Knowledge approach of the aerodynamic behavior of configurations with vortex dominated flow fields Configurations 1. Delta-wing-configuration with movable trailing-edge flaps 2. X-31 CFRP and Remote-Control-Model with remote controlled flaps, rudder and canard for maneuver simulations on the Model-Positioning-Mechanism (MPM) at NWB Folie 13 > HLRS 2005 > A. Schütte

14 Experimental Simulation Wind tunnel facilities Transonic Wind Tunnel Göttingen (TWG) Test section 1x1m Mach number range: (with perf. walls) Re = (based on 0.1 s) Low Speed Wind Tunnel Braunschweig (NWB) Test section m Mach number range: (for open test section) Re = 1.8 x 106 (based on 0.1 s) Folie 14 > HLRS 2005 > A. Schütte

15 Experimental Simulation Wind tunnel models Delta-wing-configuration with trailingedge flaps Internal 6-component piezo-balance Piezo-resistive pressure sensors at 60% and 80% chord length Control device velocity up to 300 /s X-31 configuration with remote controlled control devices CFRP fuselage, steel wing and aluminum made control devices 8 internal servo engines for control device movement Internal 6-component strain gauge Pressure sensors for measuring the unsteady pressure distribution at 60% and 70% chord length Internal 64 channel 16 bit telemetric system for data transfer Folie 15 > HLRS 2005 > A. Schütte

16 MPM - Model Positioning Mechanism Maneuver simulation in the wind tunnel Synchronized, dynamic similar movement of model and control devices in comparison to flight tests Parallel kinematics Steward platform connected to electromagnetic linear motors by 6 rods of constant length Folie 16 > HLRS 2005 > A. Schütte

17 Folie 17 > HLRS 2005 > A. Schütte

18 Numerical Results Guided coupled simulation of CFD and CSM Coupled free-to-roll maneuver simulation of CFD, CSM and Flight Mechanics Coupled free-to-roll maneuver of delta-wing-configuration with movable trailing-edge flaps (CFD-FM-Coupling) X-31: first steady calculations Folie 18 > HLRS 2005 > A. Schütte

19 Numerical Results (1) Delta wing guided rolling motion around longitudinal axis CSM-TAU-Coupling FE-Model of delta-wing and rear sting support Folie 19 > HLRS 2005 > A. Schütte

20 Numerical Results (1) Delta wing guided rolling motion around longitudinal axis CSM-TAU-Coupling Folie 20 > HLRS 2005 > A. Schütte

21 Numerical Results (2) Delta wing guided rolling motion around longitudinal axis CSM-TAU-FM-Coupling Folie 21 > HLRS 2005 > A. Schütte

22 Numerical Results (3) Delta wing free-to-roll motion around longitudinal axis TAU-FM-Coupling Ma = 0.5 Re = 3.8Mio Θ = 17 Φ 0 = 0 η = ±5 Folie 22 > HLRS 2005 > A. Schütte

23 Numerical Results (3) Delta wing free-to-roll motion around longitudinal axis TAU-FM-Coupling Folie 23 > HLRS 2005 > A. Schütte

24 Numerical Results (3) Delta wing free-to-roll motion around longitudinal axis TAU-FM-Coupling Flap up Flap down cl OΦ O Folie 24 > HLRS 2005 > A. Schütte

25 Numerical Results (4) Flow simulation around X-31 configuration (clean wing) α=14 α=18 α=22 Folie 25 > HLRS 2005 > A. Schütte

26 Numerical Results (4) Flow topology of X-31 (clean wing) Oil Flow Picture Tau-Calculation Ma=0.12 Re=1.0Mio a=18 separation line attachement line Folie 26 > HLRS 2005 > A. Schütte

27 Numerical Results (4) Flow simulation around X-31 configuration PSP-Measurement: Re = 2.07Mio α =18 TAU-Calculation: Re = 2.07Mio α =18 Folie 27 > HLRS 2005 > A. Schütte

28 HPC Requirements and Resources (1) Calculation times and resources today Folie 28 > HLRS 2005 > A. Schütte

29 HPC Requirements and Resources (2) Requirements on HPC Cluster-Hardware Maneuver Simulation X-31 configuration, movable control devices ~30 Million grid points unsteady simulation with DLR-TAU-Code CFD / CSD / FM Maneuver simulation of 2 seconds real time Aim: 2 weeks Approximation on target platform HWW-Cluster Strider (64 Proc, 64 Bit): 30 Mio. grid points 2 s real time, 2000 physical time steps, 600 inner Iterations ~ 950 h wall clock ~ 40 days on HWW-Cluster Strider (64 Proz) ~ 14 days on Cluster with > 256 Processors Herbstmaneuver: 10 s Folie 29 > HLRS 2005 > A. Schütte

30 Summary Development strategy for the prediction of the behavior of maneuvering aircraft Simulation environment and its elements Experimental simulation for validation data base First results showing the capability of time-accurate coupling of CFD/FM- and CFD/CSD/FM-Coupling First CFD results of the complex flow topology over the X-31 configuration Need for HPC resources were demanded Folie 30 > HLRS 2005 > A. Schütte