Diston, Dominic John (1999) Unified modelling of aerospace systems: a bond graph approach ...

148 Pages·2009·62.98 MB·English

Diston, Dominic John (1999) Unified modelling of aerospace systems: a
bond graph approach. PhD thesis.

http://theses.gla.ac.uk/1729/

Copyright and moral rights for this thesis are retained by the author

A copy can be downloaded for personal non-commercial research or
study, without prior permission or charge

This thesis cannot be reproduced or quoted extensively from without first
obtaining permission in writing from the Author

The content must not be changed in any way or sold commercially in any
format or medium without the formal permission of the Author

When referring to this work, full bibliographic details including the
author, title, awarding institution and date of the thesis must be given

Glasgow Theses Service
http://theses.gla.ac.uk/
[email protected]
Systems:
Unified Modelling Aerospace
of
A Bond Graph Approach
Dominic John Diston
Thesis for degree Doctor Philosophy
the
submitted of of
in Electronics Electrical Engineering
and
University Glasgow
the
at of
January 1999
Copyright @ British Aerospace 1999
pic
Preface
The intention behind dissertation is different from doctoral in
this to offer something other research
It builds "picture" Vehicle Systems Integradon
aerospace systems engineering. a of and asks questions
individual "system
about the role of systems within a of systems" and about the role of mathematical
in helping how is The key issue to be
models engineers to understand such a system composed.
is feasibility for behaviour insight into
the
addressed the of a common notation representing system and
integrated design be
that
can gained as a result.
Systems be functionality be duplication be
can given a unified purpose, can shared and needless can
but here In is 'open"in
the
avoided the problem starts! the absence of segregation, a system sense
....
Correct
be freely between
information
the energy and can exchanged constituent systems. control of
failure
is dependent
one system then on correct control of other systems and effects can propagate
boundaries.
across system
Many from footnote in history
years now, this will probably warrant a the of science and technology
fuss Right issue is is
and people will wonder what all the was about. now, this unresolved and there
little
integrated
practical experience of modelling systems, potentially extending to the so-called virtual
aircraft.
This dissertation draws
sets out an approach to the modelling which expressly together many types of
into A hypothetical has been invented for
system one process. air vehicle this purpose, containing
functionally diverse The
interactive
and systems which are typical of many advanced vehicle concepts.
interesting because lot into
technical
problems are a of systems are squeezed a compact airframe.
Traditional disciplines (e. hydraulic) becoming
g. mechanical, electrical, are more closely related and
(e. 'Modelling' key
is integrating
generic skills g. simulation, control) will play a more prominent role. a
because it deals functionality,
technology the
with performance and operability of complete systems.
The for has business,
in
this twenty the
motivation work grown out of almost years aerospace covering
in Aerodynamics, Structural Dynamics, Flight Control, General Systems Advanced Projects.
periods and
Experience has been Buccaneer F-4 Phantom (in days), Harrier, Nimrod
the
gained on and good old
MRA4, into Integrated Flight/Propulsion Control Computer-Aided Control
as well as research and
Engineering. As be different from
those
such, my perspectives may of other researchers not
--
better just different! Hopefully, it does
necessarily or worse, all who read this work will agree that
justice
to
real engineering.
Happy Reading!
Summary
Thesis
the
of
Sy'stems Integration is basis for improving
widely accepted as the the efficiency and performance of
The is build
many engineering products. aim to a unified optimised system not a collection of
hoc This design boundaries in
in
that traditional and,
subsystems are combined some ad manner. moves
doing, from integrated
integrated
so enables a structured evolution an system concept to an system
product.
It be handled
is inherent
recognised that the complexity cannot effectively without mathematical
The large but large
is
the
modelling. problem not so much the number of components rather very
functional interfaces The involved high if improved
number of that result. costs are and, the claims of
be (or
efficiency and performance are to affordable even achievable), predictive modelling and analysis
in
will play a major role reducing risk.
A framework is integrated development from
modelling required which can support system concept
This building 'system' demonstrating
inside
through to the
certification. means a a computer and
feasibility development The is
of an entire cycle. objective to provide complete coverage of system
functionality in design before becoming locked into full development
so as to gain confidence the a
investment
programme with associated capital and contractual arrangements.
With in is First, demonstrate
these points mind the purpose of this thesis threefold. to the application
bond framework for Second,
of graphs as a unified modelling aerospace systems. to review the main
bond
involved justify
the to the the
principles with modelling of engineering systems and selection of
flow (ie. dynamics)
graph notation as a suitable means of representing the power the of physical
Third, bond it into
systems. to present an exposition of the graph method and to evolve a versatile
for
integrated
notation systems.
The based field
is integration is
originality of the work on the recognition that systems a relatively new
interest body literature Apparently, is
there
of without a mature of academic or reported research. no
literature
open on the modelling of complete air vehicles plus their embedded vehicle systems which
deals issues integrated dynamics To bond be
with of and control. this end, graph concepts need to
developed in direction in facilitate intuitive
and extended new order to an approach to the modelling of
integrated It is believed first bond
systems. that the thesis represents the attempt to use graphs to
integrated
model a complete suite of aircraft systems.
Given
in integration
the that
challenges are recognised connection with complex systems problems on
future Dependency
this thesis to to
aircraft, sets out challenge orthodox approaches modelling. on
is increase issues
mathematical modelling certain to rapidly and, while there are no new theoretical
being here, directly
issues impact
raised there are major of usability and reusability which on the ability
design ideas in Bond
to
of engineers express complicated a clear, concise manner. graphs are a
highly demonstrating Although happens
convenient and appropriate means of this principle. this thesis
deal bond
to with aerospace systems and graph models of them, the underlying principles are wholly
deal insight in integration.
types
generic and could offer a great of other of systems
Acknowledgments
British Aerospace for funding
supporting and this work.
John O'Reilly Glasgow University,
of as a patient, ever-helpful and non-intrusive supervisor.
Peter Gawthrop Glasgow University, bond
of as an enthusiatic exponent of graph modelling.
Brian Weller British Aerospace, flight (not
of as a walking encyclopedia on control and related systems
Concorde
intake
to the technical
mention air control system) and as an unselfish source of advice.
Colin Hooper British Aerospace, for bond into live
of taking a chance on allowing graphs a project as a
for
method modelling systems.
Norman Maccallum Glasgow University, for his help how
in
of generous explaining gas turbine engines
really work.
My for dragging few learning
many colleagues over the years, me up quite a curves.
My Deirdre, for PhD.
interminable
wife putting up with this seemingly
My Ciarin, Siobhin Caftlin, for help.
their
young children and many generous offers of
Contents
Title Page
Preface
Summary Thesis
the
of
Acknowledgements
iv
Contents
vi
List Figures
of
viii
List Tables
of
Chapter Introduction
1
1.1 Motivation
2
1.2 Purpose
2
1.3 Originality
3
1.4 Layout Thesis
the
of
4
1.5 Philosophy
4
1.6 Overall Summary
Chapter 2 The Role Modelling in Aerospace Systems
of
2.1 Introduction
5
2.2 What is System?
a 5
2.3 Motivation for System Modelling
10
2.4 System Structure
11
2.5 System Development Context
14
2.6 Interim Summary
21
2.7 What is Model?
a 21
2.8 A Model Model
of a 25
2.9 Model Verification Validation
and 26
2.10 Towards Unified Philosophy
a 27
2.11 Candidate Methods
28
2.12 Conclusion: Feasibility Unified Modelling Method
of 31
Chapter 3 Principles Bond Graph Modelling
of
3.1
Basic Concepts
32
3.2
Primitive Components for Energy-Conserving
Systems
34
3.3
Primitive Class Definitions
35
3.4 Principles Causal Augmentation
of
37
3.5
Example
37
3.6 Pseudo-bond Graphs
40
3.7 Amplifiers Signals
41
and
iv
47
3.8
Bond Graph Summary
55
3.9
Bond Graph Superstructures
57
3.10 Information Model for Bond Graphs
60
3.11
More Examples
63
3.12
Conclusion: A Revised Bond Graph Method
Chapter 4 Bond Graph Model Libraries
4.1
Introduction
64
4.2
General Principles
65
4.3
Domain-Specific Issues 65
4.4 68
Presentation Style for Libraries
69
4.5 'Generic'
Library
72
4.6 'Hydraulic'
Library
77
4.7 Thermofluid'
Library
89
4.8
'Electrical'
Library
92
4.9 'Flight
Dynamic' Library
102
4.10
Conclusion: Building Blocks!
Chapter 5 The Virtual Aircraft
5.1
Introduction
103
5.2
Air Vehicle Description
105
5.3
Propulsion
110
5.4
Environmental Control 113
5.5 Fuel Management 114
116
5.6 Electrical Power
119
5.7
Hydraulic Power
121
5.8 Actuation
123
5.9
Vehicle System Integration
125
5.10 Model Initialisation
125
5.11 Conclusion: Towards Virtual Aircraft
the
Chapter 6 Conclusions
6.1 Overview 126
127
6.2 Conclusions
128
6.3 Recommendations
130
6.4 And Finally.....
References 131
V
List
Figures
of
Figure Title Page
2/ Standard Operational Concepts 7
22 Definition Terms 8
of
2.3 Steps in MDO Approach 12
the
2.4 Extract Information Model for System Development is
of
2.5 Traceability for Development Context 16
a
2.6 Control Design 'Activity Triangles' 18
2.7 Control Design 'Structured Iterations' 19
28 Designation Model Properties 22
of
2.9 Traditional 'Model' Development 22
2.10 Polymorphic Modelling 23
in
terms
of encapsulated components
2.11 Extract Information Model for System "Modelling" 25
of
"Modelling 26
2.12 Dynamic System"
of a
2.13 Validation Verification 26
and
2.14 Comparison Network Model Notations 30
of
3.1 Inter-relationship between Bond Graph Variables 33
33
3.2 Basic Notation
34
3.3 Primitive Bond Graph Objects
3.4 Causal Augmentation Bond Graphs 37
of
38
3.5 Mass-Spring-Damper
3.6 Bond Graph Domains (with isations) 40
possible special
41
3.7 Amplifiers
42
3.8 Signal Bond Notation
3.9 Output Signal Buffering 42
3.10 Input Signal Buffering 42
3.11 Generic Signal Modulation 43
43
3.12 Flow Effects due Effort Amplification
to
43
3.13 Imposed Effort Constraint
43
3.14 Flow-balanced Imposed Effort Constraint
44
3.15 Effort-Bicausal Transformer
44
3.16 Signal/Power Interfacing
44
3.17 Signal/Power Interface Examples
45
3.18 Signal/Signal Interfacing
45
3.19 Incoherent Interface Examples
45
3.20 Signal Buffers
45
3.21 BOOLEAN Components
46
3.22 GT Components
46
3.23 LT Components
46
3.24 SWITCH Component
Tank Over-fill Protection 46
3.25 Example:
Model Structure 47
3.26 Generic
Definition
Component 48
3.27 Standard
Definitions
Component 49
Examples
3.28
of
Component Instances
49
Examples
3.29
of
vi
3.30
Simple 49
Hierarchical Model
3.31
Standard 49
Bond Definitions
3.32
Simple Hierarchical Model Composite Bonds so
using
3.33
Concept
Through Ports 51
of
3.34 Component
Definition based Through Ports 51
on
3.35 Bond Attributes for Port Binding 53
3.36 Conflicts
in Port Binding Bond Attributes 53
of
3.37 Algebraic Loop Mechanism 54
3.38 Breaking Algebraic Loop 54
an
3.39 Standard Bond Graph Concepts 57
3.40 Generalised Bond Graph Concepts 58
3.41 Extended Bond Graph Concepts 59
3.42 Overview Unified Information Model for Bond Graphs 60
of a
3.43 Bond Graph Model Gas Turbine Engine 61
of a
3.44 Hydraulic Example 62
4.1 Domain Compatibility for Transport Process 66
a
4.2 Domain Compatibility for Thermofluid Process 67
a
4.3 'Generic' Library Components 71
4.4 Typical Pump Characteristics 73
4.5 'Hydraulic' Library Components 76
4.6 'Thermofluid' Library Components 88
47 'Electrical' Library Components 91
48 'Flight Dynamic' Library Components 100
S/ Air Vehicle Integration 104
52 Aircraft General Arrangement 106
53 STOVL Flight Regimes 106
5.4 Main Thermofluid Systems 107
5.5 Main Power Systems 108
5.6 Fuel Management System 108
57 Integrated Vehicle System 109
5.8 Gas Turbine Model View: Turbomachinery 110
5.9 Gas Turbine Model View: Bleed Flows III
5.10 Gas Turbine Model View: Fuel System III
5.11 Engine Component Library 112
5.12 Reaction Control System Model 112
5.13 Environmental Control System Model 114
5.14 Fuel Management System Model 116
5.15 Fuel System Library Components 117
5.16 Electrical Power System Model 118
5.17 Electrical Component Library 118
5.18 Hydraulic Power System Model 120
519 Hydraulic Component Library 120
520 Flight Control Actuation Model 122
5.21 Integrated Vehicle System Model 123
vii
List
Tables
of
Table Title Page
Z/ General Terminology 6
22 Modelling Issues in System Assessment 10
2.3 System Architectural Hierarchy 11
2.4 Possible Content Traceability Tables 16
of
2.5 Modelling Issues for Two-Dimensional Information 17
3.1 Standard Bond Graph Variables 32
4.1 Pseudo-Bond Graph Variables for Transport Process 66
a
42 Pseudo-Bond Graph Variables for Thermofluid Process 67
a
4.3 Standard Manoeuvre definitions 101
5.1 Major Types Aviation Fuel 115
of
52 Typical Fuel Additives 115
53 Typical Fuel Contaminants 116
54 Hydraulic Fluids 119
5.5 Hydraulic Fluid Additives 121
56 Components Integrated Vehicle System Model 123
of an
viii