ZONAIR Analysis for JSF Flight Loads P. C. Chen D. H. Lee D. D. Liu 7430 E. Stetson Drive, Suite...

ZONAIR Analysis for JSF Flight Loads

P. C. ChenD. H. LeeD. D. Liu

7430 E. Stetson Drive, Suite 205, Scottsdale, AZ 85251-3540, Tel (480) 945-9988, Fax (480) 945-6588, E-mail: [email protected]

ZPC19/Lockheed/ZONAIR

ZONAIR Analysis for JSF Flight Loads

• A ZONAIR JSF panel model has been generated from the CFD surface mesh provided by LMCO

• JSF NASTRAN model solution was provided by LMCO to give– Generalized mass and stiffness matrices for flexible loads– Grid points for spline

• Two sets of trim analysis were performed– Rigid loads computed by ZONAIR– Rigid loads interpolated from CFD solutions to ZONAIR panels

• NASTRAN static analysis was performed using the NASTRAN FORCE/MOMENT bulk data cards generated by ZONAIR trim analysis

• Sectional loads (shear, bending moment, and torsion) and elastic-to-rigid ratio of CL, CM, etc. were generated.


ZONAIR Panel Model• ZONAIR panel model is generated as follow

– Creating surface geometry from the JSF CFD surface mesh using PATRAN– Generating CQUAD4 and CTRIA3 applying mapped mesh on the surface geometry

• Panel edge alignment with hinge lines of control surface is modeled• Flow-through boundary condition is specified on the inlet panels

CFD GRID ZONAIR (4314 PANELS)


Comparison of Cp between ZONAIR and CFD solutions at M=0.9, AoA=0.0 deg.

CFD ZONAIR


Interpolated Cp on ZONAIR Panels from CFD Solutions at M=0.9, AoA= 0.0 deg.

• The interpolated CFD Cp is used as the rigid loads for flexible load analysis

T

R IK q G AIC G x q F F

Stiffness matrix from NASTRAN

Spline matrix

AIC matrix computed by ZONAIR

Rigid loads

Inertia loads

ZONAIR+CFDCFD


Generation of SPLINE Matrix• The thin plate spline method (3D spline) is used to generate the spline matrix

• ZONAIR outputs graphical files to allow visual inspection of the accuracy of the spline matrix

Mode 4

Mode 5

Mode 6

NASTRAN Modes Deformed ZONAIR Modes14.254 Hz

15.009 Hz

16.582 Hz


Flexible-to-Rigid Ratio v.s. Dynamic Pressure at =0.90

CL CM

CLh CMh


Trim Analysis at M=0.90 and Sea Level

• 9.0 g pull-up is specified as the trim conditions– Two trim equations: Lift=9.0g and moment=0.0– Two trim variables: angle of attack and horizontal tail deflection angle

• Two sets of trim analysis are performed: rigid loads computed by ZONAIR and interpolated from CFD solutions

Rigid load by ZONAIR

=12.673o

=24.988o

=13.771o

=26.182o

Rigid load by CFD


Sectional Loads of 9g Pull-Up at M=0.90, Sea Level

ZONAIR

ZONAIR + CFD

ZONAIR

ZONAIR + CFD

ZONAIR

ZONAIR + CFD

Sectional Shear Force

Sectional Bending Moment

Sectional Torsional Moment about ¼ Chord


NASTRAN Static Analysis using ZONAIR Generated Loads

• ZONAIR trim analysis generates loads in terms of NASTRAN FORCE/MOMENT bulk data cards at structural grid points– User can insert the file into the NASTRAN input deck for

subsequent detailed stress analysis


Ease of Adding Underwing Stores

• Two macroelements can be specified:– CAERO7: thin wing modeling with thickness effects simulated by source

sheet– BODY7: automated panel/grid generation of body of revolution

• Pylons and store fins can be modeled by CAERO7 and store body can be modeled by BODY7

Front View

ZONAIR Analysis for JSF Flight Loads P. C. Chen D. H. Lee D. D. Liu 7430 E. Stetson Drive, Suite...

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