CDF analysis and six degree-of-freedom modeling of the aerodynamic effects of ejection seat ...

151 Pages·2015·5.14 MB·English

by  Thomas J. Marquette

Lehigh University
Lehigh Preserve
Theses and Dissertations
1996
CDF analysis and six degree-of-freedom modeling
of the aerodynamic effects of ejection seat
stabilization devices
Thomas J. Marquette
Lehigh University
Follow this and additional works at:http://preserve.lehigh.edu/etd
Recommended Citation
Marquette, Thomas J., "CDF analysis and six degree-of-freedom modeling of the aerodynamic effects of ejection seat stabilization
devices" (1996).Theses and Dissertations.Paper 433.
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Marquette,
Thomas J.
CFD Analysis and
Six Degrees-Of
Freedom
. Modeling ...
October 13, 1996
CFD ANALYSIS AND SIXDEGREE-OF-FREEDOMMODELING
OF THE AERODYNAMIC EFFECTS OFEJECTION SEAT STABILIZATION
DEVICES
by
Thomas 1. Marquette
AThesis
Presented to the Graduate and Research Committee
ofLehigh University
in Candidacy for the Degree of
Master ofScience
10
Mechanical Engineering
LehighUniversity
August 1996

ACKNOWLEDGMENTS
I would liketo thank mywife, Dawn, for allowing me the opportunity to pursuethis
Degreewhile raising ourthreeyoung children.
The development ofCFD methodologies for ejection seat analysis was due to the
dedication and expertise ofMr. SamiHabchi, Mr. StaceyRock, and Mr. GaryHufford of
CFDResearch Corp. underNavy SBIR contracts.
The development ofthe ACCESS codefor ejection seat six degree-of-freedom analysis
was completedbyMr. Charles Yeiser and Mr. Mitchell Oslon ofConrad Technologies,
Inc. underNavy contracts.
111
TABLE OF CONTENTS
TITLEPAGE .
CERTIFICATE OF APPROVAL 11
ACKN"OWLEDGMENTS iii
TABLE OF CONTENTS iv
LIST OF TABLES V
LIST OF FIGURES......................... vi
ABSTRACT 1
1.0 INTRODUCTION 2
1.1 Objective 3
1.2 Ejection SeatFunctionDescription ;.................... 3
1.3 Ejection Seat AerodynamicPerfonnanceData................................... 6
1.3.1 Axis andNotation 7
1.3.2 Longitudinal Aerodynamic Characteristics 9
1.3.3 Directional Aerodynamic Characteristics 10
1.3.4 AircraftProximityEffects 11
1.4 Ejection SeatFull DynamicPerfonnanceData.................................. 23
1.4.1 Ejection SeatPerfonnance Criteria 23
1.4.2 Ejection Seat TestData ;..................... 24
1.5 Ejection Seat StabilizationMethods 29
1.5.1 DrogueParachute 29
1.5.2 ControllablePropulsion Concepts 30
1.5.3 DrogueBoom 32
1.5.4 Yaw StabilizationFins 33
2.0 COMPUTATIONALMETHODS 36
2.1 SIXDEGREE-OF-FREEDOMMODEL 36
2.1.1 General Fonnulation 37
2.1.2 PropulsionModels 38
2.1.3 AerodynamicModel........................................................... 40
2.1.4 ParachuteModel................................................................ 40
IV
2.1.6 StabilizationFinModel 46
2.2 CFD MODEL 53
2.2.1 GoverningEquations 53
2.2.2 Turbulent FlowModel 55
2.2.3 DiscretizationMethods 59
2.2.4 Flow SolutionProcedure..................................................... 61
2.2.5 Boundary Conditions........................................................... 62
2.2.6 Grid GenerationTechniques............ 64
2.2.7 Procedure for Calculation ofAerodynamic Coefficients...... 65
2.2.8 Previous CFD Applications to BlutfBodyProblems 66
3.0 RESULTS 71
3.1 CFD ANALYSIS OFBASELINE CONFIGURATION 71
3.1.1 Baseline Surface Geometry and Grid Generation................ 72
3.1.2 Baseline CFD Analysis....................................................... 73
3.1.3 Comparison ofAerodynamic Coefficients.......................... 75
3.2 CFD ANALYSIS OF STABILIZATIONFIN CONFIGURATION .. 93
3.2.1 Ejection Seat with StabilizationFin -
Surface Geometry and Grid Generation 93
3.2.2 Ejection Seatwith StabilizationFin - CFD Analysis 94
3.2.3 Comparison ofAerodynamic Coefficients........................... 95
3.3 SIXDEGREE-OF-FREEDOM ANALYSIS 108
3.3.1 ConditionMatrix 108
3.3.2 6DOF Simulation Results 109
4.0 CONCLUSION............................................................................................. 116
APPENDIX A 118
APPENDIX B....................... 124
REFERENCES 129
VITA 132
v
LIST OF TABLES
Table Description
1-1 Orientation AngleDefinition 7
1-2 AerodynamicForce Coefficient Definition 8
1-3 AerodynamicMoment Coefficient Definition 8
1-4 Human Physiogical AccelerationLimits 24
3-1 CFD solution matrix, BaselineConfiguration, Mach 0.30 74
3-2 CFD solution matrix, BaselineConfiguration, Mach 0.75 " 74
3-3 Comparison ofSideForce Aero Coefficients 96
3-4 StabilizationFin SimulationParameters........................................ 109
VI
LIST OF FIGURES
Figure Description
1-1 Navy Aircrew CommonEjection Seat 5
1-2 ReferenceFramefor Ejection Seat Aerodynamic Data 9
1-3 AxialForceCoefficient, Mach= 1.2, Beta= 0.............................. 14
1-4 Normal Force Coefficient, Mach=1.2, Beta=0.......................... 15
1-5 PitchMoment Coefficient, Mach= 1.2, Beta= 0.......................... 16
1-6 SideForce Coefficient, Mach=1.2, Alpha=0 17
1-7 Roll Moment Coefficient, Mach = 1.2, Alpha= 0 18
1-8 YawMoment Coefficient, Mach=1.2, Alpha=0 19
1-9 AircraftProximityEffects on Axial Force Coefficent 20
1-10 AircraftProximityEffects onNormal Force Coefficent 21
1-11 AircraftProximityEffects onPitchMoment Coefficent 22
1-12 Ejection SeatLinear Accelerations, KEAS = 0 25
1-13 Ejection SeatLinear Accelerations, KEAS =600 26
1-14 Ejection SeatRotation Rate Data, KEAS =0 27
1-15 Ejection SeatRotation Rate Data, KEAS =600 28
1-16 NACES with DrogueParachute 30
1-17 Operation ofSTAPAC Propulsion Concept 33
1-18 UnstableEjection Seat in Sideslip Condition 34
1-19 StableEjection SeatwithFins 35
1-20 Conceptual Drawing ofEjection SeatWith Fins 35
2-1 Comparison ofModel Calculation Versus Test Dataof
Catapult and Rocket Motor X Acceleration 43
2-2 Comparison ofModel Calculation Versus Test Data of
Catapult and Rocket MotorZ Acceleration 44
2-3 Comparison ofModel Calculation Versus Test Dataof
DrogueParachuteForce 45
2-4 Measured Flat Plate Drag CoefficientData................................... 49
2-5 ACES IIWind Tunnel TestModel- LongBar 50
2-6 ACES IIWind Tunnel TestModel- Triangular Surface 51
2-7 Comparison ofApproximation Techniqueto Wind Tunnel Data.... 52
2-8 SchematicofControl Volume for DiscretizationMethod 60
3-1 BaselineComputational Grid and SurfaceModel,
Pitch =0°, Yaw=0°, Side View 77
3-2 BaselineComputational Grid and SurfaceModel,
Pitch =0°, Yaw=0°, Top View 78
3-3 BaselineComputational Grid and SurfaceModel,
Pitch =-30°, Yaw =0° 79
VII
3-4 Baseline Computational Grid and SurfaceModel,
Pitch== 30°, Yaw == 0° ....................................................... 80
3-5 BaselineComputational Grid and SurfaceModel,
Pitch == 0°, Yaw == 30° ...................................................... 81 .1
3-6 StaticPressureDistribution, Mach == 0.30, Front View ................. 82
3-7 StaticPressureDistribution, Mach == 0.30, Top View ................... 83
3-8 MachNumber Contours, Mach == 0.30, Top View ........................ 84
3-9 Mach Number Contours, Mach ==0.30, Side View ........................ 85
3-10 Total Pressure Contours, Mach == 0.30, Top View ........................ 86
3-11 Total Pressure Contours, Mach == 0.30, Side View ....................... 87
3-12 Comparison ofCx Coefficient, Mach == 0.30, Sideslip == 0° ........... 88
3-13 Comparison ofCz Coefficient, Mach == 0.30, Sideslip == 0° ........... 89
3-14 Comparison ofCm Coefficient, Mach == 0.30, Sideslip == 0° .......... 90
3-15 Comparison ofCy Coefficient, Mach == 0.30 ................................ 91
3-16 Comparison ofCn Coefficient, Mach == 0.30 ................................ 92
3-17 Ejection Seat With Stabilization Fin GeometryModel,
Block and FaceRepresentations .................................................. 97
3-18 Ejection Seat With Stabilization Fin GeometryModel,
LineRepresentation (Far and Near Top View) ............................ 98
3-19 Ejection Seat with StabilizationFin SurfaceModel ..................... 99
3-20 Ejection Seat With Stabilization Fin, Algebraic Grid,
Pitch == 0°, Yaw == 0° ........................................................ 100
3-21 Ejection SeatWith Stabilization Fin, Elliptic Grid,
Pitch == 0°, Yaw == 15°...................................................... 101
3-22 Ejection SeatWith StabilizationFin, StaticPressureDistribution,
Mach == 0.30, Pitch == 0, Yaw == 15 and 30 ........................ 102
3-23 Ejection Seat With StabilizationFin, StaticPressureDistribution,
Mach == 0.75, Pitch ==0, Yaw == 15 and 30 ........................ 103
3-24 Ejection Seat With StabilizationFin, MachNumber Contours,
Mach== 0.30, Pitch == 0, Yaw == 15 and 30 ........................ 104
3-25 Ejection SeatWith Stabilization Fin, Mach Number Contours,
Mach == 0.75, Pitch == 0, Yaw == 15 and 30 ........................ 105
3-26 Ejection SeatWith StabilizationFin, Total Pressure Comtours,
Mach == 0.30, Pitch == 0, Yaw == 15 and 30 ........................ 106
3-27 Ejection SeatWith StabilizationFin, Total PressureContours,
Mach == 0.75, Pitch == 0, Yaw == 15 and 30 ........................ 107
3-28 Effect ofDeploymentDistance on Sideslip Angle ........................ 112
3-29 Effect ofDeploymentDistance on Gy Acceleration ..................... 113
3-30 Effect ofFin Size and Deployment Angle on Sideslip Angle ........ 114
3-31 Effect ofFin Size and Deployment Angle on Gy Acceleration ...... 115
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