MSC Software Aeroelastic Tools. Mike Coleman and Fausto Gill di Vincenzo

Transcription

1 MSC Software Aeroelastic Tools Mike Coleman and Fausto Gill di Vincenzo

2 MSC Software Confidential 2

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6 MSC Flightloads An open architecture environment for aeroelastic loads A venue for critical loads computation and management A GUI for MSC.Nastran aeroelasticity A convenience tool for model development and creation External Aero PATRAN MSC.NASTRAN sp_wing Markers CAD Access Structure Model Aero Model Results Visualization Structural Analysis Aeroelasticity Design Optimization MSC Software Confidential 6 6 MSC.FlightLoads &

7 6DOF Spline Technology Technology developed specifically for Structure to Structure (6 DOF) load mapping and for Aero to Structure coupling. Forces and Moments are CONSERVED using spline methodology Target FE structure can be any dimension (1D beam model, 2D shell model or 3D solid model) MSC Software Confidential 7

8 HSA Toolkit Overview Complete environment to integrate CFD data in Nastran (Static Aeroelasticity SOL144) and transfer load/displacements between dissimilar meshes Plug-in to Patran and Flight Loads MSC Software Confidential 8

9 Aeroelasticity Toolkit Import 3D aerodynamic mesh and CFD pressure load as: BDF Nastran file Tecplot file CSV file Transform CFD pressure automatically into aero forces Transfer aero forces to structure (Spline6/7) and solve the structure (SOL144) Get and export aerodynamic mesh deformation MSC Software Confidential 9

10 HSA Toolkit & 6DOF Spline MSC Software Confidential 10

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13 MSC Nastran SOL400 Advanced nonlinear solution process Combines capabilities of multiple solution sequences and software components into a common solution Glue Contact 3D contact (Mechanical and Thermal) Advanced elements Advanced materials Large rotation RBEs Analysis Chaining Rotor Dynamics Boundary condition changes Nonlinear transient thermal load Temperature dependent composites Steady State Heat Transfer Transient Heat Transfer Structural-Thermal Coupling OpenFSI Nonlinear Response Optimization Etc. Topology Optimization with Contact Touching Contact Thermo-Structural Analysis with Thermo/Structural Contact Bodies MSC Software Confidential 13

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16 Forces Displacement Velocity MSC Nastran OpenFSI Service OpenFSI SCA service provides a mechanism to exchange data between fluid and structure MSC Nastran Sol 400 undergoes the structural analysis taking for INPUT the forces and gives as OUTPUT the displacements/velocities Structure is coupled with the aerodynamics by the designation of a WETTED SURFACE Co-simulation with major commercial CFD or Inhouse codes by means of the OpenFSI service Acusolve.OpenFSI MpCCI.OpenFSI Fluent OpenFOAM Star-CCM++ StarCD Flowmaster FineHexa/Turbo ZONA UVLM.OpenFSI OpenFSI Structure MD Nastran Sol 400 Aerodynamics Unsteady Vortex Lattice Method CFDcode.OpenFSI Forces Displacements Velocity OpenFSI Forces Displacements Velocity MSC Software Confidential 16

17 Nonlinear Aeroelastic Analysis Wing Flutter (LCO) HA145E benchmark Time domain solution MSC Nastran Nonlinear transient OpenFSI CFD transient Test flutter at M=.45, f=120hz* *Ref: MSC Aeroelasticity Analysis User s Guide, Sec 8.6 MSC Software Confidential 17

18 Sol 400 OpenFSI - Application Nonlinear response of a supersonic wing Supersonic generic lifting surface (M>1.1) Non linear springs defined in terms of couple as a function of rotation (axis) Damping effect External dynamic excitations «turbulent boundary layer» Aerodynamic Forces exchange Displacement & Velocity exchange CFD FEM CFD FEM 3/15/2016 MSC Software Confidential 3/15/

19 Sol 400 OpenFSI - Application Flutter Instability at M = 2.0 Supersonic generic lifting surface (M = 2.0) Linear spring Damping effect No external dynamic excitations «turbulent boundary layer» 3/15/2016 MSC Software Confidential 3/15/

20 Sol 400 OpenFSI - Application Limit Cycle Oscillation Phenomena at M = 2.0 Supersonic generic lifting surface (M = 2.0) Non linear springs defined in terms of couple as a function of rotation (axis) Damping effect External dynamic excitations «turbulent boundary layer» Nastran CFD FEM Tip response 3/15/2016 MSC Software Confidential 3/15/

21 Thanks to Prof. Joseph MORLIER and Fazila MOHD ZAWAWI for allowing us to share the model! MSC Software Confidential 21

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26 UVLM Capabilities Geometric nonlinearity at subsonic flows Time domain Aeroelastic simulation Free wake formation Lift due to vortex roll up at high angle of attack Aeroelastic response due to 1-D/2-D discrete gust and pilot input command Cp distribution from Tunnel test or CFD Stall modeling by strip method Airfoil definition NACA series or user defined Aerodynamic body modeling Aerodynamic blade component MSC Software Confidential 26

27 Transient Longitudinal Manoeuvre Analysis Aeroelastic response to a Pilot Input Command on the Elevator Pitch down and Pitch up maneuvers Flight reference condition M = 0.1 Sea Level Flight cruise velocity 25 m/s Longitudinal flight Nodes which lie on the XZ symmetry plane are constrained to move in that plane No balance along with X direction No TRIM algorithm available in UVLM Aerodynamic code Starting flight parameters for transient analysis Angle of attack and Elevator deflection evaluated by linear TRIM analysis Sol 144 α = 2.73 δ E = -2.5 MSC Software Confidential 27

28 Transient Longitudinal Manoeuvre Analysis UVLM Aerodynamic Model Lifting Surfaces Wings 10x20 boxes Stabilizer 5X10 boxes Elevator 5X10 boxes Airfoil Geometry NACA 2412 Static aerodynamic effects due to the CAMBER of the airfoil VORTICES shed into the wake from trailing edges of wings and elevator VORTICES shed into the wake from the wings, elevator and stabilizer tips It is possible to model the aerodynamic body as well - Not considered in this analysis MSC Software Confidential 28

29 Transient Longitudinal Manoeuvre Analysis Flight reference condition α = 2.73 δ E = -2.5 δ E V = 25m/s M = 0.1 Vertical displacement of the UAV center of mass Overall vertical aerodynamic load vs UAV weight Maneuver path - Front view Maneuver path - Side view Altitude lost about 1.34 m Structural and Aerodynamic solution stored RESTART Analysis MSC Software Confidential 29

30 Transient Longitudinal Manoeuvre Analysis Structural and Aerodynamic data recovered from the previous FSI simulation (δ E = -2.5 ) Aeroelastic Response to a Pilot Input Command on the Elevator Vertical displacement of the UAV center of mass Time history of the pilot input command - Elevator I II III I III II Maneuver path - Side view I t = 5:6 s δ E = 2.3 II t = 6:7 s δ E = -2.8 III t = 7:7.4 s δ E = 1.72 Maneuver path - Front view Pitch down Pitch up It is possible to evaluate the aeroelastic response delay to a control surface input TRIM algorithm with Control System Comparison with Hybrid Trim Analysis Sol144 MSC Software Confidential 30

31 Transient Longitudinal Trim Analysis Dynamic Longitudinal TRIM Analysis Flight reference condition M = 0.1 Sea Level Flight cruise velocity 25 m/s α TRIM δ E TRIM (Hybrid Trim with CFD) Longitudinal flight Nodes which lie on the XZ symmetry plane are constrained to move in that plane Nastran TRIM Algorithm developed in python Control System on the Elevator Translational Balance within X direction Translational Balance within Z direction Rotational Balance along Y axis Fz = 0 My = 0 Fx = 0 Dynamic of Flight equations to be satisfied MSC Software Confidential 31

32 Control System Algorithm α = α TRIM(Sol144) δ E = δ E TRIM(Sol144) δ E α = 4.29 deg δ E = -3.9 deg a x OpenFSI Sol400 UVLM.OpenFSI SOL 400 UVLM My, Fz, Fx = 0? No α TRIM(Sol400) δ E TRIM(Sol400) MSC Software Confidential 32

33 Aerodynamic Load [N] Aerodynamic Load [N] Transient Longitudinal Trim Analysis Aerodynamic load components - Reference coord system Load Balance z L FzWing Fx Fz a x Fz x α Wind FxWing W δ E Overall Aerodynamic Load - Fz Overall Aerodynamic Load - Fx Weight Fz Fx Time [s] Time [s] MSC Software Confidential 33

34 Displacement [m] Rotation [Degree] Transient Longitudinal Trim Analysis CG - Z displacement CG - Rotation along y Tz Ry Time [s] Time [s] Structural deformation at Trimmed condition AOA Elev Hybrid Trim AOA = 4.29 deg MSC Software Confidential 34

35 Transient Gust Response Analysis Dynamic Longitudinal Gust Response Flight reference condition M = 0.1 Sea Level Flight cruise velocity 25 m/s Dynamic Trimmed Condition Longitudinal flight Nodes which lie on the XZ symmetry plane are constrained to move in that plane Nastran TRIM Algorithm developed in python Control System on the Elevator Translational Balance within X direction Translational Balance within Z direction Rotational Balance along Y axis Fz = 0 My = 0 Fx = 0 Trim flight condition after Gust perturbation MSC Software Confidential 35

36 Transient Gust Response Analysis Results Overview Structure Aerodynamics MSC Software Confidential 36

37 Acceleration [g] Transient Gust Response Analysis Normal Load Factor Normal Load Factor Normal Load Factor Time [s] Ude = 7,62 m/s T GUST = s Structure considered to be linear Sol146 and Sol400 are in good accordance It could be possible to take into account for nonlinearities MSC Software Confidential 37

38 Displacement [m] Transient Gust Response Analysis After the Gust the Aircraft get again the Trimmed Flight condition thanks to the Control System Without Control With Control CG - Z Displacement Gust Excitation Trimmed Flight Trimmed Flight Time [s] It could be possible to act on Airelons to reduces load on Wings Gust Alleviation MSC Software Confidential 38

39 Nonlinear Aeroelastic Analysis MSC Nastran Structural Model UVLM Aerodynamic Model Geometry Span of m Constant chord of 2.44 m 10 degrees dihedral angle at ends Two pods at 2/3 of from the mid-span Kg Central pod weighs 254 Kg. Overall weight of about Kg FEM Shells for the wing Solid for pods Aerodynamic 12 panels chordwise 30 panels spanwise Vortices shed from trailing edge and wing tip All six DOFs of the mid-span central section constrained to be zero. Gravity is not considered MSC Software Confidential 39

40 Nonlinear Aeroelastic Analysis Flight condition Vertical displacement of Wing Tip M = 0.1 Sea Level Flight cruise velocity 12.5 m/s a = 16 Max vertical deflection of about 18 m No dynamic instability found Wake propagation - Ortho view Structural deformation - Front view MSC Software Confidential 40

41 Thank You and Any Questions?