ZONAIR Analysis for JSF Flight Loads

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ZONAIR Analysis for JSF Flight Loads
P. C. Chen D. H. Lee D. D. Liu
7430 E. Stetson Drive, Suite 205, Scottsdale, AZ
85251-3540, Tel [phone], Fax (480)
945-6588, E-mail pc_at_zonatech.com
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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.

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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)
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Comparison of Cp between ZONAIR and CFD solutions
at M0.9, AoA0.0 deg.
ZONAIR
CFD
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Interpolated Cp on ZONAIR Panels from CFD
Solutions at M0.9, AoA 0.0 deg.

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

AIC matrix computed by ZONAIR
Stiffness matrix from NASTRAN
Inertia loads
Spline matrix
Rigid loads
CFD
ZONAIRCFD
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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

NASTRAN Modes
Deformed ZONAIR Modes
14.254 Hz
Mode 4
15.009 Hz
Mode 5
16.582 Hz
Mode 6
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Flexible-to-Rigid Ratio v.s. Dynamic Pressure at
0.90
CL?
CM?
CL?h
CM?h
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Trim Analysis at M0.90 and Sea Level

• 9.0 g pull-up is specified as the trim conditions
• Two trim equations Lift9.0g and moment0.0
• 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 CFD
Rigid load by ZONAIR
?12.673o
?13.771o
?24.988o
?26.182o
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Sectional Loads of 9g Pull-Up at M0.90, Sea Level
Sectional Shear Force
Sectional Bending Moment
Sectional Torsional Moment about ¼ Chord
ZONAIR
ZONAIR
ZONAIR
ZONAIR CFD
ZONAIR CFD
ZONAIR CFD
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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

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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