Virtual-Aircraft Design & Control of
TransCRuiser – S&C study with CEASIOM
Arthur Rizzi1, P. Eliasson2, T. Grabowski3, J. Vos4
1Royal
Institute of Technology (KTH), Stockholm, 100 44, Sweden
2Swedish Defence Research Institute (FOI), Stockholm, 164 90, Sweden
3Warsaw University of Technology (WUT), 00-665 Warsaw, Poland
4CFS Engineering (CFSE), 1015 Lausanne Switzerland
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
1
Contents

CEASIOM Design Tool – outcome of SimSAC
 Analyze/improve flight dynamics


Specification & Design to Canard Configuration
Creation Tabular Aero Data
 Comparison with WT data

Prediction Flying Qualities - Low & transonic speeds
 Static stability – static margin: tradeoffs
 Dynamic stability – linear & nonlinear (flight simulator)

Augmented Stability
 Demo Flight simulation
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
2
SimSAC EU-Project Partnership
NO
PARTNER
COUNTRY
1
KTH
SE
2
Alenia Aeronautica
IT
3
Bristol University
UK
4
CERFACS
FR
5
CFS Engineering
CH
6
Dassault Aviation
FR
7
DLR
DE
8
EADS-M
DE
9
FOI
SE
10
Liverpool University
UK
11
J2 Aircraft Solutions
UK
12
ONERA
FR
13
Politecnico Milano
IT
14
Saab Aerosystems
SE
15
TsAGI
RU
16
VZLU
CZ
17
Warsaw University of
Technology
PL
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
SimSAC: Simulating Aircraft Stability and Control
Characteristics for Use in Conceptual Design
EU FP 6 STREP project
Project coordinator: Prof. A. Rizzi, KTH
3
SimSAC Goal: Design Flight Control System Earlier
• Compute Aerodyn Dataset
• variable-fidelity CFD
• predict flight dynamics
• Use in conceptual design
Aerodynamic Tools for S&C
Conceptual
Design
Phase
Use of …
Preliminary
Handbook
methods
standard Very high
SimSAC Very low
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
Linear
Aerodyn
ROM
CFD &
Optimize
WT testing Flight testing
high
low
very low
Aero data
high
high
medium
4
CEASIOM Design Tool
Flight Dynamics
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
5
TCR Design: SAAB Specification
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
6
Configuration Re-Design


Original TCR: poor trim ability  large  , 
Different configurations investigated
 Wing further fore (design parameter)
 Three lifting surfaces
 All-moving canard (vary location & size)

Design of wind tunnel model
 One moving surface for longitudinal control
 No engines
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
7
Design Choice – Static stability margin
Trim condition
1
L  V 2 SCL ( ,  C )  W
2
Cm ( ,  C )  0
Static
stable
L
M
ac
CG
Dilemma !
Static margin
Ma = 0.12
0.65
0.85
0.97
Kn grows with Ma
AC = 38.9m
39.9
40.6
42.1
Response heavy at high speed
Kn = 4.7%
13.6%
19.5%
32.2%
CG = 38.3m
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
8
Predict Flying Qualities: solve Flight Dyn Eqs
Translation:
m V  ω  m V  Faero  Fprop  Fgravity
  ω  Iω  Maero
Iω
Rotation:
 L
Θ
Kinematics:
ds
1
 A F(s, t )
dt
Linearize



( stability derivatives...)
ds
 Js
dt
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
s – state vector (8)
A – inertia matrix
F – general forces
 ( A 1 F)i , j 
J

 s j

9
Faero Interpolation Process - Kriging
Aero-data
Data from
source
Tornado
WT *)
Edge
NSMB
LivMB
*) No CD
M
x
x
x

x
x
x
x
x
b
x
x
x
x
p
x
x
-
q
x
*
-
r
x
*
-
dot
x
*
-
bdot
x
*
-
deltaC
x
x
x
x
x
Database constructed
Mach
•DACE Kriging toolbox:
•Linear base model,
•Input & output scaled (0,1)
•Manual choice corr. length
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
α
10
10
Weight, Inertia & Balance
Total Length
63.87 m
Total Wingspan (bref) 44.66 m
Total Canard Span
12.00 m
Total Height
11.70 m
Fuselage Diameter
3.70 m
MAC 16.06/11.77 m, Wing reference area Sref = 489 m2,
Reference point, moment
x = 35.00 m, z = 0 m
Center of gravity
x = 38.33 m, z = 0 m
SAAB
Total Structure
65
Total Propulsion system
14
Total system
18
Empty weight
97
MTOW
210
Howe
63
14
14
91
203
Raymer
57
17
49
122
234
Cessna
46
31
57
133
245
USAF
55
17
7
79
191
Torenbeek Ceasiom
63
53
8
28
17
15
88
96
199
208
Inertias
Saab T
CEAS.0
CEAS.1
Ixx
5,17
10,35
15,17
Iyy
4,67
21,62
17,52
Izz
6,58
29,92
32,1
Ixz
1,73
0,09
0
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
W&B/ACBuilder:
J.Munoz, S Ricci, ...
11
11
Aero Data & Handling Qualities – Longitudinal Dynamics
Cm() for zero
canard deflection
WT data
Comparison
Control authority:
Canard stall
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
12
12
Trim & Flying Qualities – low speed
Trim Sensitivity
small
Phugoid

M.50
M.35
Canard
120-180 m/s, 1km – 3km
M 0.35 – 0.50
Short
period
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
13
13
Trim & Flying Qualities – transonic speed

Canard
Phugoid
Short
period
Transonic
dip
M.65
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
M=1
14
Flow Physics  transonic dip
220ms
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
250
270
15
286
Linear & NonLinear Stability – Stick fixed
Eigenvalues
276 m/s 10km,  = 0.5
All modes stable (barely ...)
Wind gust
- disturb α
 small
 large
Flight simulation
 = -0.3o: Slooowly damped
 = -3.0o: See-saw pitchup ... Cobra manuver
Time Histories
: AoA
q: attitude
ds
 A 1 F (s, t )
dt
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
16
16
Augmented Stability
SAS OFF

q
SAS ON

q
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
17
Flying Qualities with Augmentation – low speed
Phugoid
ON
Short Period
OFF
ON
OFF
ON
Dutch Roll
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
OFF
18
Conclusions

CEASIOM proven useful !
– Trim & static margin chosen correctly
– Good canard sizing & placement
• Verified by WT  no major pitfalls
– Stability Augmentation  good flying qualities
• Low-speed stick-fixed qualities improved
• Transonic disturbance damped
• Canard authority sufficient
– Allows concept designer to work with control tools to sort out:
• What can be fixed by control system
• What changes in configuration is needed

CEASIOM lives on !
– Community of users  Open software
– Visit www.ceasiom.com
– Join us !
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
19
Thanks
For Your Attention !
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
20
CEASIOM Predicts T-tail Flutter
Clamped node
Stick Model: beam
elements & lump masses
Fin bending mode 1 1.6 Hz
Hor. Tail roll mode 3 4.3 Hz
Flutter frequency [Hz]
Mach
SMARTCAD
NASTRAN®
0.50
3.46
3.61
0.70
3.43
3.56
0.85
3.38
3.49
0.97
3.25
3.39
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
21
V-g diagrams, sea-level
Aircraft Motion: Non-Linear Dynamical System
Translation:
m V  ω  m V  Faero  Fprop  Fgravity
  ω  Iω  Maero
Iω
Rotation:
 L
Θ
Kinematics:
ds
1
 A F(s, t )
dt



linearize
ds8
 J 8s 8
dt
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
s – state vector (8)
A – inertia matrix
F – general forces
1

  ( A8 F)i , j 

J8  


s


j


22
WT Model
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
23
Airspeed, Altitude & Mach number
M.97
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
24
24
What if done by Handbook Method
Raymer volume coefficient
lC S C
cC 
MAC  S
~ 0.1
lC = 28 m
SC = 60 m2
MAC = 11.77 m
Handbook methods not
applicable to unconventional
configs. such as the TCR
cC ≈ 0.29
S = 489 m2
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
25
TCR Design: Specification
Payload
‘Loose ideas’ to be
Worked out:
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
MTOW~ 180 t , R~ 10000 km ,
No Pax~ 200
Mc = 0.97
26
Mach
Fused Aerodynamic Dataset

Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
27
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
28
Mach
Fused Aerodynamic Dataset
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010

29
TCR - CFDsim - Mach dependence

Evolution of pitching moment & lift coefficients with Mach/speed

Also breakpoints – no second-opinion – do we believe CFD ??
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
30
Design Loops
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
31
Design Process
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
32
Flight Simulation – Transonic Cruise
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
33
Baseline Design


Initial sizing with Saab in-house
method.
Baseline design: input for
CEASIOM.
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
34
CEASIOM Design Analysis: XML params
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
35
TCR T-tail flutter
Clamped node
Stick Model: beam
elements & lump masses
Modal frequencies [Hz]
Mode SMARTCAD NASTRAN®
1
1.60
1.60
2
2.63
2.62
3
4.32
4.34
4
4.63
4.59
5
8.16
8.16
6
8.71
8.69
7
13.32
13.25
8
18.87
18.10
9
18.93
18.76
Flygteknik-2010 – Norra Latin
10
20.07
21.48
Stockholm, 18-19 Oct 2010
Fin bending mode 1 1.6 Hz Hor. Tail roll mode 3 4.3 Hz
Flutter dynamic pressure [Pa]
Mach SMARTCAD NASTRAN®
0.50
5.66∙104
6.55∙104
0.70
5.54∙104
6.43∙104
0.85
5.43∙104
6.16∙104
0.97
5.38∙104
5.92∙104
Mach
0.50
0.70
0.85
0.97
Flutter frequency [Hz]
SMARTCAD
NASTRAN®
3.46
3.61
3.43
3.56
3.38
3.49
3.25
3.39
36
V-g diagrams, M∞=0.50,
sea-level
Trim & longitudinal static stability
Results from SDSA, for h=10 km and V = 240 m/s (M=0.8)
xW
xC
SC
[m2]
[deg]
TCR-C2
0.26
0.13
65
TCR-C17
0.26
0.017
TCR-C8
0.26
TCR-C15
0.26
Config.
trim [deg]
Static
margin
(%MAC)
2.7
9.0
4.54
65
2.0
6.2
-2.88
0.017
47
1.5
9.2
4.26
0.12
72
2.5
8.2
3.13
TCR-C2
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
trim
TCR-C17
37
Trim & longitudinal static stability
Results from SDSA, for h=10 km and V = 240 m/s (M=0.8)
xW
xC
SC
[m2]
[deg]
TCR-C2
0.26
0.13
65
TCR-C17
0.26
0.017
TCR-C8
0.26
TCR-C15
0.26
Config.
trim [deg]
Static
margin
(%MAC)
2.7
9.0
4.54
65
2.0
6.2
-2.88
0.017
47
1.5
9.2
4.26
0.12
72
2.5
8.2
3.13
TCR-C17
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
trim
TCR-C8
38
Trim & longitudinal static stability
Results from SDSA, for h=10 km and V = 240 m/s (M=0.8)
xW
xC
SC
[m2]
[deg]
TCR-C2
0.26
0.13
65
TCR-C17
0.26
0.017
TCR-C8
0.26
TCR-C15
0.26
Config.
distance W-C
SC
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
trim [deg]
Static
margin
(%MAC)
2.7
9.0
4.54
65
2.0
6.2
-2.88
0.017
47
1.5
9.2
4.26
0.12
72
2.5
8.2
3.13
C ,
39
trim
static margin
Construct Windtunnel Model
• Exterior shape
- Export IGES
• PoliMi designed
interior structure
Flygteknik-2010 – Norra Latin
Stockholm, 18-19 Oct 2010
40