М.Г.Гоман, А.В.Храмцовский, М.Шапиро «Разработка моделей аэродинамики и моделирование динамики самолета на больших углах атаки», доклад на международной конференции «Тренажерные технологии и обучение», прошедей в ЦАГИ, г.Жуковский, 24-25 мая 2001 г. M.Goman, A.Khramtsovsky and M.Shapiro "Aerodynamics Modeling and Dynamics Simulation at High Angles of Attack", presentation at the International conference on Simulation Technology & Training held at TsAGI, Zhukovsky (Russia), on 24 May 2001.

1. 24 May, 2001 Simulation Technology & Training 1
Aerodynamics Modeling and Dynamics
Simulation at High Angles of Attack
M.Goman, A.Khramtsovsky and M.Shapiro
Central Aerohydrodynamic Institute (TsAGI), Zhukovsky, Russia

2. 24 May, 2001 Simulation Technology & Training 2
Contents:
• Introduction
• Closed-loop research & development cycle
• General structure of the mathematical model
• Aerodynamics modeling
• Nonlinear dynamics analysis
• Control laws design
• Simulation & pilot training
• Conclusion

3. 24 May, 2001 Simulation Technology & Training 3
TsAGI Research/Training Simulators

4. 24 May, 2001 Simulation Technology & Training 4
Research & Development Cycle
Flight
Tests
Simulation
&
Stability
&
Dynamics
Analysis
Control
Laws
Design
Aerodynamics
Modelling Pilot Training

5. 24 May, 2001 Simulation Technology & Training 5
General Structure of Aircraft
Mathematical Model
Equations
of motion
Undercarriage
model
Aerodynamic
forces and moments
model
Aerodynamic
characteristics
database
Atmospheric
turbulence
model
Engine model
Altitude-velocity
engine characteristics
Cockpit
Control system
and actuator
models
Flight tests
safety equipment

6. 24 May, 2001 Simulation Technology & Training 6
Wide-Range Aerodynamics Model
Aerodynamics
Model:
o
o
o
Static tests
Forced
oscillation
tests
tests
Rotary balance
Flight tests
Free spin tests
(Vertical wind
tunnel M=1:16)
Large-scale
controlled models
(flight tests M 1:4)

7. 24 May, 2001 Simulation Technology & Training 7
Anti-Spin Parachute Model
a
a
b
b
X
Z
Y
V
p
p
p
p
r
p
F
lp
V
V
V
p
p
p
p
p
p
p
= V0 + +
+
+
+
+
rp
pp
pp
p
p
p
p p
p
l
l
d
d t
= -
[ ]
(r )
)F
F
= CD S
S
(
2
2
M = r
w
r

8. 24 May, 2001 Simulation Technology & Training 8
Qualitative Analysis of Nonlinear Aircraft Dynamics

9. 24 May, 2001 Simulation Technology & Training 9
Deep Stall and
Unrecoverable Flat Spin Regimes
Pitchmomentcoefficient
Pitchmomentcoefficient
Full pitch-up control
Full pitch-up control
Full pitch-down control
Full pitch-down control
Deep stall
lock-inNormal flight regimes
(stable with FCS)
Deep stall regimes Unrecoverable flat spin regimes
Flat spin
lock-in
C
C
m
m
Angle of Attack Angle of Attack
I
I
Ix
y
z-
sin2a2
inertia moment
Angle of Attack
Cn asym
Potential function analogy
Normal flight regimes
Critical regimes
Rocking control
p r
Yawmoment
Aerodynamic
yaw asymmetry

10. 24 May, 2001 Simulation Technology & Training 10
Aerodynamic Yaw Asymmetry (X-31)
Data range
-.10 -.05 0 .05 .10
20
30
40
50
60
70
80
Angleofattack(deg)
C n0
.06 .08
Flight Tests

11. 24 May, 2001 Simulation Technology & Training 11
Flat Spin Due To Aerodynamic Asymmetry

12. 24 May, 2001 Simulation Technology & Training 12
Pitch Rocking Control for Spin Recovery
Timeofrecovery(sec)
0
10
20
30
40
50
0 0.05 0.10 0.15
with rocking
without
rocking
Yaw asymmetry Cn0
Potential function analogy
Normal flight regimes
Critical regimes
Rocking control

13. 24 May, 2001 Simulation Technology & Training 13
Spin Prevention & Recovery Control System
Conventional
Control Laws
Spin Prevention
& Recovery
Algorithms
Spin Entry
& Recovery
Identification
a,b,V,p,q,r
d

14. 24 May, 2001 Simulation Technology & Training 14
Deep Stall Departure and Recovery

15. 24 May, 2001 Simulation Technology & Training 15
Flat Spin Departure and Recovery

16. 24 May, 2001 Simulation Technology & Training 16
Cobra Maneuver Simulation

17. 24 May, 2001 Simulation Technology & Training 17
Unsteady Nonlinear Aerodynamic Modeling

18. 24 May, 2001 Simulation Technology & Training 18
High Incidence Flight Simulation of a
General Aviation Aircraft

19. 24 May, 2001 Simulation Technology & Training 19
Canard Flow Separation &
Pitch Self-Sustained Oscillations
Low angle of attack
High angle of attack
Attached flow
Canard separated
a
q
q
X
X
e
thr
18
6
4
16
-3
3
0
(deg/s)
(deg)

20. 24 May, 2001 Simulation Technology & Training 20
Concluding Remarks:
• Piloted simulation of an aircraft dynamics at high
angles of attack is extremely important element of the
aircraft development and sertification processes
• Piloted simulation helps in assessment of aerodynamic
model, accompanying flight tests, and training of rank-
and-file pilots

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Desktop Training Simulator

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Research & Training Flight Simulator

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Medium-Size Training Simulator