Study of aerodynamic technology for VSTOL fighter/attack aircraft: Vertical attitude concept

258 Pages·2008·12.7 MB·English

by  Copier User

https://ntrs.nasa.gov/search.jsp?R=19790001855 2019-03-26T22:36:00+00:00Z
-
NASA CR 152131
N A S A C O N T R A C T O R
R E P O R T
STUDY OF AERODYNAMIC TECHNOLOGY
FOR VSTOL FIGHTERIATTACK AIRCRAFT
-
VER TICAL A TTITUDE CONCEPT
H. A. Gerhardt, W. S. Chen
NOR THROP CORPaRA TION, AIRCRAFT GROUP
Hawthorne, GT.
for Amer Remrch Center
NATIONAL AEROWAUTIC$ NO WAGE ADMINISTRATION WMHIN6TON, 0. C. * MAY 1871
e
-
NORTHROP CORPORTION, AIRCRAFT GROUP 11. Contrm or Gmnt No.
HAWTHORNE, CAL. NAS2-9771
13. Typr of Report md Period Covered
12. S-ing AO~KV kmo .nd NASA, Ames Research Center, ' NCoovn t1rac t"7o'7r -FMinaayl R3$e,p-o $r7t 8
Moffett Field, Calif. 94035, David Taylor Naval Ship
14. Sponsoring Awcy Cock
Research & Development Center, Bethesda, Md. 20084
15. Supplemmtarv Notes -
Ames Research Center Technical Monitor W. P, Nelms [phone] .
-
NSRDC Point of Contact R. L. Schaeffer [phone]
16. Abstract
A study is made of the aerodynamic technology for a vertical attitude VSTOL
(VATOL) supersonic fighter/attack aircraft. The selected configuration features a
tailless clipped delta wing with le,ading-edge extension (LEX), maneuvering flaps,
top-side inlet, twin dry engines and vectoring nozzles. A relaxed static stability is
employed in conjunction with the maneuvering flaps to optimize transonic performance
and minimize supersonic trim drag. Control for subaerodynamic flight is obtained by
gimballing the nozzles in combination with wing tip jets.
Emphasis is placed on the development of aerodynamic characteristics and the
identification of aerodynamic uncertainties. A wind tunnel test program is proposed
to resolve these uncertainties and ascertain the feasibility of the conceptual design.
Ship interface, flight control integration, crew station concepts, advanced weapons,
avionics, and materials are discussed.
17. Key Words (SugggWd by Author(st I 18. Oistribution Statement
19. Security k i f .( of this report) 20. Security Classif. (of this prOal 21. No. of Pages 22. Price"
Unclassified Unclassified
I
*For sale by th. National Technicrl Infornution Srvice. Springfield, Virginia 22161
SUMMARY
A study is made of the aerodynamic technology for a vertical attitude VSTOL
(VATOL) supersonic fighter /attack aircraft. The selected configuration features a
tailless clipped delta wing with leading-edge extensian (LEX), maneuvering flaps,
top-side inlet, twin dry engines and vectoring nozzles. A relaxed static stability is
employed in conjunction with the maneuvering flaps to optimize transonic performance
and minimize supersonic trim drag. Control for subaerodynamic flight is obtained
.
by gimballing the nozzles in combination with wing tip jets
Emphasis is placed on the development of aerodynamic characteristics and
the identification of aerodynamic uncertainties. A wind tunnel test program is .
proposed to resolve these uncertainties and ascertain the feasibility of the conceptual
design. Ship interface, flight control integration, crew station concepts, advanced
weapons, avionics, and materials are discussed.
Aerodynamic uncertainties which have been identified include LEX
effects on lift and flow to the topside inlet, aerodynamics center shift, high
angle-of-attack characteristics, supersonic wave drag estimation, supersonic
maneuvering flaps, and jet spray effects on takeoff and landing.
iii
SYMBOLS
a. c. Aerodynamic Center
Aircraft Longitudinal Acceleration
"1
a Aircraft Normal Acceleration
n
AR Aspect Ratio
a Aircraft Longitudinal Acceleration
X
a Aircraft Lateral Acceleration
Y
Aircraft Vertical Acceleration
az
c' Mean Aerodynamic Chord
c.g., C.G. Center of Gravity
Drag Coefficient
C~
Flat Plate Skin Friction Drag Coefficient
c%
Drag-Due-to-Lift Coefficient
C D ~
Minimum Drag Coefficient
'Dmin
Viscous Drag Coefficient
Incremental Drag Due to Reynolds Number Variation
Flat Plate Skin Friction Coefficient
Lift Coefficient
Lift at Zero Angle-of -Attack
Buffet Onset Lift Coefficient
Maximum Lift Coefficient
Rolling Moment Coefficient
Pitching Moment Coefficient
Pitching Moment at Zero Lift
Yawing Moment Coefficient
Side Force Coefficient
Oswald Spanload Efficiency Factor
Net thrust
F~
g Acceleration due to Gravity
h Altitude
Roll Moment of Inertia
Ixx
Pitch Moment of Inertia
IYY
Yaw Moment of Inertia
Izz
L /D Lift to Drag Ratio
1 Length
M Mach Number
m.a.c. Mean Aerodynamic Center
n Normal Load Factor
z
0.P . R. Overall Pressure Ratio
Specific Excess Power
Ps
P¶q , r Angular Rates About Aircraft's Y, X, and Z Axes
4 Dynamic Pressure
AP Pilot's Pedal Displacement
Reynold1s Number
R~
Force at Left and Right Wingtip Reaction Jets
R ~ R'~
S Area
Leading-Edge Extension Exposed Area
'LEX
SM Static Margin
Asp, AsR Pilot's Fore-Aft and Lateral Stick Displacement
Wing Reference Area
SW* 'ref
Component Wetted Area
'wet
T Thrust
Commanded Thrust from Left and Right Engines
T ~T~~~ ,
-
AT, ,A TR Pilot's Throttle Levers Left and Right Engines
Thrust from Rear Left and Right Nozzles
TRL~T RR
Aircraft Velocity Components Along X, Y, and Z Axes
Wing Loading
Pilot's Vertical Speed Command Switch
Aircraft Position with Respect to an Earth Reference
Stall Speed
Weight
Angle-of- Attack
Angle-of-Sideslip
Ratio of specific heats
Trailing Edge Flap Deflection
Leading Edge FIap Deflection
Elevator, Aileron and Rudder Angles
Commanded Elevator, Aileron and Rudder Angles
Thrust Deflection
2
Pitch Acceleration (rad Isec )
Aircraft Pitch Attitude
Leading Edge Sweep
Fore-Aft Deflection Angle of Forward Nozzle
Deflection Angle of Rear Nozzles
Lateral Deflection Angle of Forward Nozzle
Commanded Forward Nozzle Angle
Commanded Rear Nozzle Angle
Aircraft Roll Attitude
2
Roll Acceleration (rad lsec )
Aircraft Heading
CONTENTS
...................................
SUMMARY
...................................
SYMBOLS
.................................
TABLES viii
...
...............................
ILLUSTRATIONS
................................
INTRODU CTlON
..........................
2.1 Design Philosophy
..........................
2.2 Design Guidelines
...............
2.3 Aircraft Arrangement Description
..................
AERODYNAMIC CHARACTERISTICS
.............................
3.1 Wing Selection
..............................
3.2 Longitudinal
........................
3.2.1 Minimum Drag
.......
3.2.2 Basic Lift. Drag. and Pitching Moment
.............
3.2.3 Longitudinal Stability Analysis
........................
3.2.4 Trim Analysis
3.2.5 Longitudinal High ar Aerodynamic
.......................
Characteristics
..........
3.2.6 Aerodynamic Control Effectiveness
....................
3.2.7 Wing-Body Camber
...................
3.3 Lateral /Direc tional Analysis
..............
3.3.1 Lateral/Directional Stability
3.3.2 ~ateral/DirectionalC ontrol
........................
Effectiveness
....................
3.4 Propulsion Induced Effects
..........................
3.5 Controls Blending
....................
4 PROPULSION CHARACTERISTICS
................
4.1 Engine Selection and Description
..........................
4.2 Propulsion Trades
.........................
4.3 Air Induction System
....................
4.4 Topside Flow Field Effects
............
4.5 Exhaust Nozzle/Aft End Design Approach
..............
4.6 Engine Installation Loss Assessment
vii
CONTENTS (Continued)
SECTION
..................
4.7 Installed Engine Performance
.. .........................
4 8 Reaction Controls
............................
5 AIRCRAFT DESIGN
.................
5.1 Structural Design and Analysis
......................
. 5.1.1 Design Criteria
...................
5.1.2 Structural Materials
..................
5.1.3 Structural Description
....................
5.1.4 Structural Analysis
.......................
5.2 Flight Control System
-
5.2.1 Hover and Transition Regimes
.....................
Normal Operation
......
5.2.2 Engine Failure in Hover or Bansition.
..............
5.2.3 Conventional Flight Regime
..........................
5.3 Mass Properties
.....................
5.3.1 Weight Estimates
...........................
5.3.2 Balance
....................
5.3.3 Moments of Inertia
.............................
5.4 Crew Station
....................
5.4.1 Design Philosophy
..................
5.4.2 Crew Seat Positioning
..............................
5.5 Subsystems
.......................
6 AIRCRAFT PERFORMANCE
........................
6.1 Flight Performance.
.......................
6.1.1 Data Summary
6.1.2 Thrust LoadingIWing LoadinglAircraft Sizing
....................
6.1.3 Sensitivity Studies
........................
6.2 Takeoff and Landing
......................
6.2.1 Control Concept
....................
6.2.2 Takeoff Transition
....................
6.2.3 Landing Transition
....................
6.2.4 Short Takeoff (STO)
..........
6.2.5 Conventional Takeoff and Landing
viii
CONTENTS (Continued;!
.
SECTION PAGE
7 AERODYNAMIC UNCERTAINTIES
................
7.1 Wave Drag at High Mach Number
................
7 .. 2 Leading Edge Extension Related
....................
7.3 Aerodynamic Center Shift
........................
7.4 High Angle of Attack
..........
7.5 . Maneuvering Flaps at Supersonic Speeds
.............................
7.6 Topside Inlet
.............................
7.7 Buffetonset
.........................
7. 8 Other Uncertainties
................
7.8.1' Inlet Effect on Wing Drag
............
7.8.2 Inlet Effect on Afterbody Drag
..........................
7.8.3 JetSpray
...................
PROPOSED RESEARCH PROGRAM
.........................
8.1 Research Objectives
......................
8.2 Wind-Tunnel Test Plan
................
8.3 Wind-Tunnel Test Model Design
............
8.3.1 Powered Simulator Installation
................
8.3.2 Wind Tunnel Installation
...............
8.3.3 Aerodynamic Force Model
.....................
8.3.4 Jet Effects Model
......................
8.3.5 Model Support
.......................
8.3.6 Model Balance
...............................
CONCLUSIONS
. . . . . . . . . . . . . . . . . . . . . . . . .
10 REFERENCES
LIST OF TABLES
Number .Page
. . . . . . . . . . .
1 1 Supersonic VSTOL Concept Differences 1-2
. . . . . . . . . . .
3-1 Minimum Drag Buildup by Component 3-21
. . . . . . . . . . . .
3-2 Viscous Drag Buildup by Component 3-22
.
. . . * . * . . . .
3-3 Drag .Due to Lift with No Camber. M1 2 3-23
. . . . . . . . . . . . . . . . .
3-4 Geometry Design Modes 3-23
. . . . . . . .
3-5 Drag Due to Lift with Design Camber. M 1.2 3-24
. . . . . . . . . . . . . . . . . . . .
3-6 Spray Height Data 3-25
3-7 Nozzle Conditions for Calculating VATOL
. . . . . . . . . . . . . . . . . . . . . . .
Spray Height
. . . . . . . . . . . . . . . .
Fighter Escort Sizing Mission
. . . . . . . . . . . . . . .
Propulsion Loss Assessment
. . . . . . . . . . . . . . . . . .
Group Weight, Statement
. . . . . . . . . . . . . . . . . .
Baseline Avionics Suite
.. . .. .. . . .. .......... .
Typical Fighter Escort Mission , , , ,
- . ..... ... ..... . . . . ....
Test Plan 11 Ft and 9 x 7 Ft Tunnels , ,
. . . . . . . . . . . . . . . . . .
Test Plan 12 Ft Tunnel
. . . . . . . . . . .
Comparison Model Size to Tunnel Size