Virtual-Aircraft Design & Control of TransCRuiser – S&C study with CEASIOM

Flygteknik-2010 – Norra LatinStockholm, 18-19 Oct 2010 1

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, Sweden2Swedish Defence Research Institute (FOI), Stockholm, 164 90, Sweden

3Warsaw University of Technology (WUT), 00-665 Warsaw, Poland4CFS Engineering (CFSE), 1015 Lausanne Switzerland


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


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

PLEU FP 6 STREP projectProject coordinator: Prof. A. Rizzi, KTH

SimSAC: Simulating Aircraft Stability and Control Characteristics for Use in Conceptual Design


SimSAC Goal: Design Flight Control System Earlier

Design Conceptual

Phase Preliminary

Use of … Handbook methods

Linear Aerodyn

ROM CFD & Optimize

WT testing Flight testing

standard Very high high low very low Aero data

SimSAC Very low high high medium

• Compute Aerodyn Dataset• variable-fidelity CFD• predict flight dynamics

• Use in conceptual design

Aerodynamic Tools for S&C


CEASIOM Design Tool

Flight Dynamics


TCR Design: SAAB Specification


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


Design Choice – Static stability margin

0),(

),(2

1 2

Cm

CL

C

WSCVL

Trim condition

CGac

M

Static margin

LStatic stable

Ma = 0.12 0.65 0.85 0.97

AC = 38.9m 39.9 40.6 42.1

Kn = 4.7% 13.6% 19.5% 32.2%

CG = 38.3m

Kn grows with Ma

Response heavy at high speed

Dilemma !


Predict Flying Qualities: solve Flight Dyn Eqs

s – state vector (8)

A – inertia matrix F – general forces

gravitypropaero FFFVωV mmTranslation:

aeroMIωωωI Rotation:

LΘKinematics:

),(1 tdt

dsFA

s

Jss

dt

d

j

ji

s,

1 )( FAJ

Linearize ( stability derivatives...)

Flygteknik-2010 – Norra LatinStockholm, 18-19 Oct 2010 10 10

Faero Interpolation Process - KrigingAero-data

M b p q r dot bdot deltaCTornado - x x x x x x x xWT *) - x - x * * * * xEdge x x x - - - - - xNSMB x x x - - - - - xLivMB x x x - - - - - x*) No CD

Database constructed•DACE Kriging toolbox:•Linear base model,•Input & output scaled (0,1)•Manual choice corr. length

Data from source

Mac

h

α


Total Length 63.87 mTotal Wingspan (bref) 44.66 mTotal Canard Span 12.00 mTotal Height 11.70 mFuselage 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 mCenter of gravity x = 38.33 m, z = 0 m

SAAB Howe Raymer Cessna USAF Torenbeek CeasiomTotal Structure 65 63 57 46 55 63 53Total Propulsion system14 14 17 31 17 8 28Total system 18 14 49 57 7 17 15Empty weight 97 91 122 133 79 88 96MTOW 210 203 234 245 191 199 208

Inertias Saab T CEAS.0 CEAS.1Ixx 5,17 10,35 15,17Iyy 4,67 21,62 17,52Izz 6,58 29,92 32,1Ixz 1,73 0 0,09

W&B/ACBuilder: J.Munoz, S Ricci, ...

Weight, Inertia & Balance


Control authority: Canard stall

WT data

Comparison

Cm() for zero canard deflection

Aero Data & Handling Qualities – Longitudinal Dynamics


120-180 m/s, 1km – 3kmM 0.35 – 0.50

M.35 M.50

Canard

Phugoid

Shortperiod

Trim & Flying Qualities – low speed

Trim Sensitivity small


M.65

Canard

M=1

Trim & Flying Qualities – transonic speed

Phugoid

Shortperiod

Transonic dip


220ms 250 270 286

Flow Physics transonic dip


Eigenvalues276 m/s 10km, = 0.5All modes stable (barely ...)

Flight simulation = -0.3o: Slooowly damped = -3.0o: See-saw pitchup ... Cobra manuver

AoA

attitude

Linear & NonLinear Stability – Stick fixed

Time HistoriesWind gust - disturb α small large

),(1 tdt

dsFA

s


Augmented Stability

SAS OFF

SAS ON


ON

OFF ONOFF

OFF

ON

Phugoid Short Period

Dutch Roll

Flying Qualities with Augmentation – low speed


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 !


Thanks

For Your Attention !


CEASIOM Predicts T-tail Flutter

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

V-g diagrams, sea-level

Clamped node


Aircraft Motion: Non-Linear Dynamical System

s – state vector (8)

A – inertia matrix F – general forces

gravitypropaero FFFVωV mmTranslation:

aeroMIωωωI Rotation:

LΘKinematics:

),(1 tdt

dsFA

s

888 sJ

s

dt

d

j

ji

s,

18

8

)( FAJ

linearize


WT Model


M.97

Airspeed, Altitude & Mach number


What if done by Handbook Method

Raymer volume coefficient

Handbook methods not applicable to unconventional

configs. such as the TCR

SMAC

Slc CC

C ~

0.1

lC = 28 m

SC = 60 m2

MAC = 11.77 m

S = 489 m2

cC ≈ 0.29


TCR Design: Specification

MTOW~ 180 t , R~ 10000 km ,No Pax~ 200 Mc = 0.97

‘Loose ideas’ to beWorked out:

Payload


Fused Aerodynamic Dataset

Mac

h



Fused Aerodynamic Dataset

Mac

h


Evolution of pitching moment & lift coefficients with Mach/speed Also breakpoints – no second-opinion – do we believe CFD ??

TCR - CFDsim - Mach dependence


Design Loops


Design Process


Flight Simulation – Transonic Cruise


Baseline Design

Initial sizing with Saab in-house method.

Baseline design: input for CEASIOM.


CEASIOM Design Analysis: XML params


TCR T-tail flutter

Modal frequencies [Hz]Mode SMARTCAD NASTRAN®

1 1.60 1.602 2.63 2.623 4.32 4.344 4.63 4.595 8.16 8.166 8.71 8.697 13.32 13.258 18.87 18.109 18.93 18.76

10 20.07 21.48

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

Flutter frequency [Hz]Mach SMARTCAD NASTRAN®0.50 3.46 3.610.70 3.43 3.560.85 3.38 3.490.97 3.25 3.39 V-g diagrams, M∞=0.50,

sea-level

Clamped node

Stick Model: beam elements & lump masses

Fin bending mode 1 1.6 Hz

Hor. Tail roll mode 3 4.3 Hz


Trim & longitudinal static stability

Results from SDSA, for h=10 km and V = 240 m/s (M=0.8)

Config. xW xC SC [m2] trim [deg] trim [deg] Static margin

(%MAC)

TCR-C2 0.26 0.13 65 2.7 9.0 4.54

TCR-C17 0.26 0.017 65 2.0 6.2 -2.88

TCR-C8 0.26 0.017 47 1.5 9.2 4.26

TCR-C15 0.26 0.12 72 2.5 8.2 3.13

TCR-C2 TCR-C17





(%MAC)

TCR-C2 0.26 0.13 65 2.7 9.0 4.54

TCR-C17 0.26 0.017 65 2.0 6.2 -2.88

TCR-C8 0.26 0.017 47 1.5 9.2 4.26

TCR-C15 0.26 0.12 72 2.5 8.2 3.13

TCR-C17 TCR-C8





(%MAC)

TCR-C2 0.26 0.13 65 2.7 9.0 4.54

TCR-C17 0.26 0.017 65 2.0 6.2 -2.88

TCR-C8 0.26 0.017 47 1.5 9.2 4.26

TCR-C15 0.26 0.12 72 2.5 8.2 3.13

C , static margin SC

distance W-C


Construct Windtunnel Model

• Exterior shape - Export IGES

• PoliMi designed interior structure

Documents

Virtual-Aircraft Design & Control of TransCRuiser – S&C study with CEASIOM