Stirling Dynamics

Modelling and

Simulation

Int roduct ion

• Specialist engineering and design services

• Mechatronic systems

• Serving aerospace, marine, energy and defence

• 26+ years trading history

• US and UK bases

• Focus on innovation and value

© 2014 Stirling Dynamics

3

B u s i n e s s Fo c u s

© 2014 Stirling Dynamics

Training &

Simulation

Active Hand

Controls

G-Seats

Pallet Solutions

Standard

Products

Custom Designs

Aerospace

Services

Modelling and

Simulation

Landing Gear

Systems

Structures &

Materials

Flight Sciences

Test Services

Submarine

Systems

Steering & Diving

Control Systems

Submarine

Autopilots

Hover Systems

Systems

Engineering

Trials Support

Energy Systems

Condition

Monitoring

System

Water Purification

Systems

Sub Sea Analysis

Office Locations

© 2013 Stirling Dynamics 4

Orlando

Seattle

Farnborough

Bristol

Yeovil

O f f i c e L o c a t i o n s

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U S a n d U K b a s e s

Major Customers

M a j o r C u s t o m e r s

© 2014 Stirling Dynamics

© 2008 Stirling Dynamics 6

M o d e l l i n g a n d S i m u l a t i o n C a p a b i l i t y

D y n a m i c s , C o n t r o l a n d Pe r f o r m a n c e

© 2014 Stirling Dynamics

Core Stirling capability:

• 20+ engineers (10 PhDs)

• Mathematical modelling of mechanical, hydraulic, pneumatic and

electrical systems

• Analysis of kinematics, dynamics, stability and control

Capability applied to:

• Fuel systems

• Landing gear systems

• Flight control systems

Modelling and analysis frequently lends itself to off-site packaging:

• Fully delegated service – all skills and tools available in-house

• All processes adhere to AS/EN9100, ISO 9001

A e r o s p a c e S e r v i c e s – E n g i n e e r i n g

M o d e l l i n g a n d S i m u l a t i o n C a p a b i l i t y

D y n a m i c s , C o n t r o l a n d Pe r f o r m a n c e

Robust approach to modelling and simulation:

• Requirements capture and decomposition

• Model specification

• Verification and validation planning

System performance analysis:

• Steady state and transient behaviour

• Time domain and frequency domain analysis

• Normal operation and failure mode analysis

© 2014 Stirling Dynamics

© 2008 Stirling Dynamics 8

M o d e l l i n g a n d S i m u l a t i o n C a p a b i l i t y

D y n a m i c s , C o n t r o l a n d P e r f o r m a n c e

© 2014 Stirling Dynamics

Industry standard tools:

• Matlab, Simulink

• SimScape,

SimMechanics,

SimHydraulics

• Real-Time Workshop

(e.g. for xPC, VxWorks,

RTLinux targets)

• EASY5, AMESim

• ADAMS

• LabView

© 2014 Stirling Dynamics

Software development:

• HTML

• JavaScript

• SQL

• Fortran

• C, C++

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© 2014 Stirling Dynamics

M e c h a n i c a l S y s t e m s

I n - F l i g h t R e f u e l l i n g H o s e S i m u l a t i o n

In-Fight Refuelling Hose Simulation:

• Dynamic hose response in flap vortex wake

• Modelling of hose mechanical properties

• Modelling of aerodynamic lift and drag

• Model validation against wind tunnel data

• De-risk new aircraft design

2

Out

1

In

B F

Revolute Joint

1/s

[alpha]

CS1

CS4

CS2

CS3

CG

Element Mass

v

Body Sensor

(local axis)

av

Body Sensor

(World axis)

Body Actuator

Measurements Torque

Bending Stiffness and Damping

Body x v elocity

Body y v elocity

Angle rel to Earth

Ux

Uy

alpha

Airstream Velocity Calculations

Ux

Uy

Fy

Fx

Aero Loading

Body axis x v elocity

Body axis y v elocity

Angle relativ e

to Earth

Fy

Fx

Body axis loads

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© 2014 Stirling Dynamics

H y d r a u l i c S y s t e m s

F i g h t C o n t r o l s , L a n d i n g G e a r a n d Fu e l

S y s t e m s

Modelling analysis support:

• Airframe manufacturers (system integrators)

• Systems suppliers (e.g. landing gear, flight controls)

Electronic Control

Unit

LVDT

Power Drive

Electronics

Duplex Valve

Duplex Actuator

Position

Demand

Aircraft Hydraulic Supply 1

Aircraft Hydraulic Supply 2

LVDT

Valve

Coil Power Drive

Electronics

Electronic Control

Unit

Applied Load

• Flight Control Systems

• Landing Gear Systems

• Fuel Systems

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© 2014 Stirling Dynamics

H y d r a u l i c S y s t e m s

P r i m a r y F l i g h t C o n t r o l s

Basic Analysis:

• Preliminary design review

• Linear modelling

• Simplex representations

• Design concept evaluation

ramVelocity

2

ramPosition

1PSS

Unequal spool

P

Pr

xv

A

B

Supply

Pressure

-C-

f(x)=0PSS

PSS

PSS

Mechanical

Load

R

C

E

Ideal Hydraulic

Pressure Source

S

TP

Double -Acting

Hyraulic Actuator

A

B

P

V

R

C

Custom Hydraulic

Fluid

valvePosition

1

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.450

0.2

0.4

0.6

0.8

1

1.2

1.4

Step Response

Time (sec)

Am

plit

ude

-80

-60

-40

-20

0

20

Magnitu

de (

dB

)

100

101

-720

-540

-360

-180

0

Phase (

deg)

Bode Diagram

Gm = 11.8 dB (at 6.4 Hz) , Pm = 66.6 deg (at 1.69 Hz)

Frequency (Hz)

Detailed Analysis:

• Critical design review

• Fluid friction, non-linear flow, temperature dependency

• Multiplex design

• Failure mode performance

• Non-linear frequency response

• Control system design

• Comprehensive performance evaluation against

requirements

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© 2014 Stirling Dynamics

H y d r a u l i c S y s t e m s

L a n d i n g G e a r S y s t e m – S i m u l i n k /

S i m H y d r a u l i c s

Dynamic representations of:

• Servo-valve

• By-pass valve

• Accumulator piston

• Hydro-mech model of steering system

• Required to establish baseline aircraft level

performance

• Steer, tow and free-to castor modes

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

-5

0

5

10

15

20

25

NLG

Time [s]

Th

eta

[d

eg

]

thetaTT

thetaST

Command

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

-10

0

10

20

30

40

Time [s]

W [d

eg

/s]

wTT

wST

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© 2014 Stirling Dynamics

H y d r a u l i c S y s t e m s

L a n d i n g G e a r E x t e n d S e q u e n c i n g A n a l y s i s –

E A S Y 5

Analysis accounting for:

• Temp range -50 to +90 C

• Laminar/turbulent flow

• Dissolved air and cavitation

• In-service problem

• Modification for improved sequencing of

ext/ret actuator and uplocks

• Modelling and analysis to support sizing of

new sequencing canisters

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© 2014 Stirling Dynamics

C o - S i m u l a t i o n o f H y d r o - M e c h a n i c a l S y s t e m s

L a n d i n g G e a r E x t e n d a n d R e t r a c t – A D A M S a n d

A M E S i m

Co-simulation of mechanics and hydraulics

• ADAMS – flexible multi-body kinematics

• AMESim – detailed hydraulic performance

Modelling of full extend/retract system

• Landing gear, doors, ramps guides, hydraulics

• Flexible landing gear and doors

• Aerodynamics, joint frictions, contacts

Performance analysis of integrated system

• Performance under “normal” operation

• Failure mode performance (free-fall, missing tyre, missing wheel,

uplock failure, pitch trimmer failure and combinations)

• Loads analysis

• Support to certification

© 2014 Stirling Dynamics

A i r c r a f t Fu e l S y s t e m s

D i s p e n s e P u m p P r e s s u r e C o n t r o l Pe r f o r m a n c e

Requirement for closed loop pressure control:

• Development and validation of dispense pump

Requirements:

• Pump hydrodynamic model

• Controller functional and analogue

electronic design

• Validation of existing and revised pump

controller design

0 10 20 30 40 50 600

5

10

15

20

25

30

35

40

45

50

T/hr

Eta

(%

)

Hydraulic Efficiency Vs Flow

2200rpm

4400rpm

6600rpm

8800rpm

• Key interface between customer design team and

manufacturer

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A i r c r a f t Fu e l S y s t e m s -

A c c u m u l a t i o n a n d Tr a n s p o r t a t i o n o f Wa t e r i n

Fu e l

Development of an analysis tool for modelling the accumulation and transportation of water

within an aircraft fuel system:

mw ma

wallwm _

Pull, SHull,, Vull, Tull

downm *

* Positive flow directions

Pup, SHup

flowup SHm ,

SAE International

Wright Brothers medal winner

• Model accounting for; condensation, suspension,

dissolution and transportation

• Analysis tool for evaluating water management

requirements for different flight missions and the

impact of inerting systems on water management

© 2014 Stirling Dynamics

© 2014 Stirling Dynamics

M e c h a n i c a l a n d H y d r a u l i c S y s t e m s

S u m m a r y

Mechanical and hydraulic simulation

capability:

• Simulation models developed

alongside the design

• Comprehensive assessment of

system performance – normal

and failure modes

• Models fully documented and

tested

Mechanical and hydraulic simulation

support applied to:

• Airbus fuel system closed loop pressure control

• Airbus fuel systems R&T water management

modelling

• Airbus landing gear extend/retract and steering

systems

• FRL in-flight refuelling hose dynamics

• BAE Systems active pilot controls

• Bombardier landing gear systems

• Claverham primary flight control actuator (fixed

and rotary wing)

• APPH primary flight control actuator (rotary

wing)

Head Office UK

Stirling Dynamics Limited

26 Regent Street

Clifton

Bristol BS8 4HG

United Kingdom

Tel +44 (0)117 915 2500

Head Office US

Stirling Dynamics Inc.

4030 Lake Washington Blvd NE #205

Kirkland, WA 98033-7870

USA

Tel +1 (425) 827 7476

w w w . s t i r l i n g - d y n a m i c s . c o m

© 2014 Stirling Dynamics