MSC Software Aeroelastic Tools - aerosociety.com aeroelasticity.pdf · MSC Flightloads • An open ... • It is possible to evaluate the aeroelastic response delay to a control surface

MSC Software Aeroelastic Tools

Mike Coleman and Fausto Gill di Vincenzo

MSC Software Confidential 2





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

6

External

Aero

MSC.NASTRANPATRAN

• CAD Access

• Structure Model

• Aero Model

• Results Visualization

• Structural Analysis

• Aeroelasticity

• Design Optimization

MSC.FlightLoads &

Dynamics

sp_wing Markers


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)


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


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


HSA Toolkit & 6DOF Spline




MSC Nastran SOL400

3/15/201613

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.

Touching

Contact

Glue Contact

Advanced nonlinear solution process Combines capabilities of multiple solution sequences

and software components into a common solution

Thermo-Structural

Analysis with

Thermo/Structural

Contact Bodies

Topology Optimization with

Contact




• MSC Nastran Sol 400 undergoes the structural analysis taking for INPUT the forces and gives as OUTPUT the displacements/velocities

Structure MD

Nastran Sol 400

Aerodynamics Unsteady Vortex Lattice Method

Forc

es

Dis

pla

cem

ent

Vel

oci

ty

• Structure is coupled with the aerodynamics by the designation of a “WETTED SURFACE”

UVLM.OpenFSI

CFDcode.OpenFSI

Forces

Displacements Velocity

Forces

Displacements Velocity

• Acusolve.OpenFSI• MpCCI.OpenFSI

• Fluent• OpenFOAM• Star-CCM++• StarCD• Flowmaster• FineHexa/Turbo

ZONA

• Co-simulation with major commercial CFD or In-house codes by means of the OpenFSI service

OpenFSI OpenFSI

• OpenFSI SCA service provides a mechanism to exchange data between fluid and structure

MSC Nastran OpenFSI Service

http://www.scai.fraunhofer.de/

http://www.scai.fraunhofer.de/


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

Nonlinear response of a supersonic wing

183/15/2016

Sol 400 OpenFSI - Application

3/15/2016

CFD FEM

‐ 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

FEM CFD


Flutter Instability at M = 2.0

193/15/2016


3/15/2016

‐ Supersonic generic lifting surface (M = 2.0) ‐ Linear spring ‐ Damping effect‐ No external dynamic excitations «turbulent boundary layer»


Limit Cycle Oscillation Phenomena at M = 2.0

203/15/2016


3/15/2016

Nastran

‐ 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 »

CFD FEM – Tip response


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






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


• 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

• Starting flight parameters for transient analysis

No TRIM algorithm available in UVLM Aerodynamic code

• Angle of attack and Elevator deflection evaluated by linear TRIM analysis Sol 144

Aeroelastic response to a Pilot Input Command on the Elevator

• Pitch down and Pitch up maneuvers

Transient Longitudinal Manoeuvre Analysis

• α = 2.73°

• δE = -2.5°


• VORTICES shed into the wake from the wings, elevator and stabilizer tips

• VORTICES shed into the wake from trailing edges of wings and elevator

• UVLM Aerodynamic Model

• Lifting Surfaces• Wings 10x20 boxes • Stabilizer 5X10 boxes• Elevator 5X10 boxes

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

NACA 2412

• Airfoil Geometry

• Static aerodynamic effects due to the CAMBER of the airfoil

• It is possible to model the aerodynamic body as well - Not considered in this analysis


3/15/201628


α = 2.73°

Vertical displacement of the UAV center of mass Overall vertical aerodynamic load vs UAV weight

• Altitude lost about 1.34 m

δE = -2.5° δE

• Structural and Aerodynamic solution stored RESTART Analysis

Maneuver path - Front view Maneuver path - Side view

• Flight reference condition V = 25m/s M = 0.1



Vertical displacement of the UAV center of mass

Maneuver path - Side view Maneuver path - Front view

I II III

Time history of the pilot input command - Elevator

• Structural and Aerodynamic data recovered from the previous FSI simulation (δE = -2.5°)

δE = -2.8°

δE = 2.3°

t = 6:7 s

t = 5:6 s

δE = 1.72 °t = 7:7.4 s

II

I

III

I

IIIII

• It is possible to evaluate the aeroelastic response delay to a control surface input

• TRIM algorithm with Control System

• Aeroelastic Response to a Pilot Input Command on the Elevator

Comparison with Hybrid Trim Analysis Sol144

Pitch down

Pitch up




• M = 0.1 Sea Level• Flight cruise velocity 25 m/s• αTRIM δE TRIM (Hybrid Trim with CFD)


• Nodes which lie on the XZ symmetry plane are constrained to move in that plane

• Control System on the Elevator

Nastran TRIM Algorithm developed in python

• Translational Balance within X direction

Dynamic Longitudinal TRIM Analysis

• Translational Balance within Z direction

• Rotational Balance along Y axis

Dynamic of Flight equations to be satisfied∑ My = 0

∑ Fz = 0

∑ Fx = 0

Transient Longitudinal Trim Analysis


SOL 400 UVLM

OpenFSI

α = αTRIM(Sol144)

δE = δE TRIM(Sol144)

Sol400 UVLM.OpenFSI

∑ My, ∑ Fz, ∑ Fx = 0 ?No

∆δE∆ax

αTRIM(Sol400)

δE TRIM(Sol400)

α = 4.29 degδE = -3.9 deg

Control System Algorithm


Overall Aerodynamic Load - FxOverall Aerodynamic Load - Fz

Wind

x

zL

α

FzWing

FxWing

Aerodynamic load components - Reference coord system

Fz

Fx

Load Balance

Fz

W

∆δE

∆ax

WeightFz Fx

Time [s] Time [s]

Aer

od

ynam

ic L

oad

[N

]

Aer

od

ynam

ic L

oad

[N

]



CG - Rotation along yCG - Z displacement

Tz Ry

Time [s] Time [s]

Dis

pla

cem

ent

[m]

Ro

tati

on

[D

egre

e]

Structural deformation at Trimmed condition

AOA Elev

Hybrid Trim AOA = 4.29 deg




• M = 0.1 Sea Level• Flight cruise velocity 25 m/s• Dynamic Trimmed Condition


• Nodes which lie on the XZ symmetry plane are constrained to move in that plane

• Control System on the Elevator

Nastran TRIM Algorithm developed in python

• Translational Balance within X direction

Dynamic Longitudinal Gust Response

• Translational Balance within Z direction

• Rotational Balance along Y axis

∑ My = 0

∑ Fz = 0

∑ Fx = 0

Transient Gust Response Analysis

Trim flight condition after Gust perturbation


Results Overview

Structure Aerodynamics



• Ude = 7,62 m/s • TGUST = 0.0696 s • Structure considered to be linear

Normal Load Factor

Normal Load Factor

Normal Load Factor

Acc

eler

atio

n[g

]

Time [s]

Sol146 and Sol400 are in good accordance

It could be possible to take into account for nonlinearities



After the Gust the Aircraft get again the Trimmed Flight condition thanks to the Control System

It could be possible to act on Airelons to reduces load on Wings

Without ControlWith Control

CG - Z Displacement

Time [s]

Dis

pla

cem

ent

[m]

Gust Alleviation

Trimmed Flight

Gust Excitation

Trimmed Flight



MSC Nastran Structural Model UVLM Aerodynamic Model

• Span of 72.78 m• Constant chord of 2.44 m• 10 degrees dihedral angle at ends

• Two pods at 2/3 of from the mid-span 22.69 Kg• Central pod weighs 254 Kg.• Overall weight of about 952.53 Kg

• 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

• Geometry

• Shells for the wing• Solid for pods

• FEM

• Aerodynamic



• Flight condition

• M = 0.1 Sea Level• Flight cruise velocity 12.5 m/s• a = 16

Wake propagation - Ortho view

Structural deformation - Front view

• Max vertical deflection of about 18 m

• No dynamic instability found

Vertical displacement of Wing Tip


Thank You and Any Questions?

Documents

MSC Software Aeroelastic Tools - aerosociety.com aeroelasticity.pdf · MSC Flightloads • An open ... • It is possible to evaluate the aeroelastic response delay to a control surface