CRANFIELD UNIVERSITY MICHAIL DIAKOSTEFANIS INTERNET OPERATION OF AERO GAS ...

410 Pages·2015·24.25 MB·English

CRANFIELD UNIVERSITY

MICHAIL DIAKOSTEFANIS

INTERNET OPERATION OF AERO GAS TURBINES

SCHOOL OF ENGINEERING

PhD Thesis
Academic Year: 2013 – 2014

Supervisors: Dr T. Nikolaidis, Dr M. Stillwell, Dr S. Barnes,
Pr P. Pilidis
October 2014
CRANFIELD UNIVERSITY

SCHOOL OF ENGINEERING

PhD Thesis

Academic Year 2013 - 2014

MICHAIL DIAKOSTEFANIS

INTERNET OPERATION OF AERO GAS TURBINES

Supervisors: Dr T. Nikolaidis, Dr M. Stillwell, Dr S. Barnes,
Pr P. Pilidis
October 2014

© Cranfield University 2014. All rights reserved. No part of this
publication may be reproduced without the written permission of the
copyright owner.
ABSTRACT
Internet applications have been extended to various aspects of everyday life and offer
services of high reliability and security. In the Academia, Internet applications offer
useful tools for the remote creation of simulation models and real-time conduction of
control experiments. The aim of this study was the design of a reliable, safe and secure
software system for real time operation of a remote aero gas turbine, with the use of
standard Internet technology at very low cost.
The gas turbine used in this application was an AMT Netherlands Olympus micro gas
turbine. The project presented three prototypes: operation from an adjacent
computer station, operation within the Local Area Netwok (LAN) of Cranfield
University and finally, remotely through the Internet. The gas turbine is a safety critical
component, thus the project was driven by risk assessment at all the stages of the
software process, which adhered to the Spiral Model. Elements of safety critical
systems design were applied, with risk assessment present in every round of the
software process.
For the implementation, various software tools were used, with the majority to be
open source API’s. LabVIEW with compatible hardware from National Instruments was
used to interface the gas turbine with an adjacent computer work station. The main
interaction has been established between the computer and the ECU of the engine,
with additional instrumentation installed, wherever required. The Internet user
interface web page implements AJAX technology in order to facilitate asynchronous
update of the individual fields that present the indications of the operating gas turbine.
The parameters of the gas turbine were acquired with high accuracy, with most
attention given to the most critical indications, exhaust gas temperature (EGT) and
rotational speed (RPM). These are provided to a designed real-time monitoring
application, which automatically triggers actions when necessary.
The acceptance validation was accomplished with a formal validation method – Model
Checking. The final web application was inspired by the RESTful architecture and
allows the user to operate the remote gas turbine through a standard browser,
without requiring any additional downloading or local data processing.
The web application was designed with provisions for generic applications. It can be
configured to function with multiple different gas turbines and also integrated with
external performance simulation or diagnostics Internet platforms. Also, an analytical
proposal is presented, to integrate this application with the TURBOMATCH WebEngine
web application, for gas turbine performance simulation, developed by Cranfield
University.
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Keywords:
Asynchronous, AJAX, Remote, Real-time, Spiral, Safety Critical, Risk Assessment,
Software Process, Formal Validation, Model Checking

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ACKNOWLEDGEMENTS
Theoretically this work was considered to a one researcher’s project and at the very
early stages I did have this feeling, as the subject was until then mostly unknown to
me. However, as time and work went on, I realized that I was not working alone, but in
collaboration with numerous other individuals, who contributed in different ways to
the completion of this work. It is all these people then who I wish to thank and express
my gratitude for their support.
First of all I wish to individually thank my three Supervisors, starting with Pr Pilidis, who
honoured me by trusting me and assigning me this task, which was originally his own
idea. He acted more than a Coordinator between the two involved Departments, as he
was always willing to spare his limited time with me and support me with valuable
advice and corrections.
Dr Nikolaidis, as the Power and Propulsion Supervisor, has vastly contributed to the
evaluation of the gas turbine performance aspects that should be considered for the
project.
Then it was Dr Barnes from the AMAC Group, who guided me closely during my first
steps into software engineering and was always there to listen to my numerous
questions, many of which later on I realized that they were trivial.
My special thanks to Dr Stillwell, who replaced Dr Barnes after the latter left Cranfield,
but his knowledge in Internet applications development and his patience with me,
played a major role for the accomplishment of this Thesis.
Dr G. P. Liu, from Glammorgan University. Although we met only once at an early stage
of the project, he had the kindness to demonstrate the NCSLab application, developed
under his supervision. His advice then was abstract but crucial for me.
Mr Charnley and all the Technicians in the test area for their immense support for the
use of available equipment and facilities. Also, it would be an omission not to thank Mr
Stan Collins, who had the kindness to give me some software modules he had
designed, in order to reuse them in my application.
A special reference should be addressed to Sebastian Spratt, a very talented young
man from Wootton Upper School. As a Nuffield Scholar, he designed the host web
pages of the application, based on the guidelines provided by me.
I also want to thank my lovely daughters, Antonia and Evangelia, who both not only
tolerated my absence from every day family life, but they were as well happy to help
me with minor details of the Thesis layout.
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Additionally, I have to mention the contribution of our family dog, Princess, who has
been my patient audience with whom I discussed all my newly conceived ideas for the
project, whilst we were having long relaxed walks.
Finally, there are no words to describe the contribution of my beloved wife Nektaria to
the accomplishment of this Thesis. Even with all the support that I had from Cranfield
and my Supervisors, it would never be possible for me to complete the work without
the infinite support from her. She has been there for me throughout the whole period
of my studies in Cranfield. She has shared hours with me helping me arrange this
Thesis and took on all the family obligations, while I was absorbed with my studies.
I dedicate this work to my wonderful wife Nektaria and to the memory of my parents,
Antonios and Kalliopi.

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TABLE OF CONTENTS
ABSTRACT .................................................................................................................................. i
ACKNOWLEDGEMENTS ............................................................................................................ iii
LIST OF FIGURES....................................................................................................................... ix
LIST OF TABLES ...................................................................................................................... xiv
LIST OF EQUATIONS ................................................................................................................ xv
LIST OF ABBREVIATIONS ......................................................................................................... xvi
1 INTRODUCTION ...................................................................................................................... 1
1.1 Scope .............................................................................................................................. 1
1.2 Thesis structure .............................................................................................................. 1
1.3 The AMT Netherlands Olympus gas turbine .................................................................... 4
2 AIM AND OBJECTIVES ............................................................................................................. 5
2.1 Aim ................................................................................................................................. 5
2.2 Objectives ....................................................................................................................... 5
2.3 Contribution ................................................................................................................... 5
3 LITERATURE REVIEW .............................................................................................................. 7
3.1 Similar applications and problem definition .................................................................... 7
3.1.1 Applications in the aviation sector ........................................................................... 8
3.1.2 Applications in power generation. ............................................................................ 8
3.1.3 Academic applications ........................................................................................... 11
3.1.4 The Turbomatch WebEngine .................................................................................. 14
3.2 Gas turbines and basic performance monitoring elements ............................................ 15
3.2.1 Basic principles ...................................................................................................... 15
3.2.2 Steady state and transient performance ................................................................ 16
3.2.3 Failure modes ........................................................................................................ 16
3.2.4 Gas turbine control systems ................................................................................... 18
3.3 Hazard Identification, risk analysis and risk mitigation ................................................... 20
3.3.1 Risk evaluation and mitigation ............................................................................... 20
3.3.2 Probabilistic risk analysis ........................................................................................ 22
3.3.3 Project risk analysis ................................................................................................ 22
3.4 Risk assessment and quality determination of software products.................................. 23
3.4.1 Software quality metrics ........................................................................................ 23
3.4.2 Safety critical systems ............................................................................................ 24
3.4.3 Software reliability prediction ................................................................................ 24
3.4.4 Avionics development ............................................................................................ 26
3.5 Software development .................................................................................................. 27
3.5.1 Software process models ....................................................................................... 27
3.5.2 System Requirements ............................................................................................ 29
3.5.3 Architectural design ............................................................................................... 30
3.5.4 Validation & Verification ........................................................................................ 32
3.5.5 Model checking ...................................................................................................... 33
3.6 Real time operating systems interfacing software ......................................................... 35
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3.7 Internet applications and protocols ............................................................................... 36
3.7.1 Internet data communication protocols ................................................................. 36
3.7.2 Web services and web applications ........................................................................ 37
3.7.3 HTTP requests ........................................................................................................ 39
3.7.4 File Transfer Protocol ............................................................................................. 40
3.7.5 TCP and UDP .......................................................................................................... 40
3.8 Performance and security over the web ........................................................................ 40
3.8.1 Internet threats ..................................................................................................... 40
3.8.2 Internet security .................................................................................................... 41
3.8.3 Network performance ............................................................................................ 43
4 SOFTWARE PROCESS, REQUIREMENTS AND ARCHITECTURE ................................................. 46
4.1 Software Process .......................................................................................................... 46
4.1.1 The Spiral as the Software Process Model .............................................................. 46
4.1.2 Adaptation of the Spiral to the present project ...................................................... 48
4.2 System Requirements ................................................................................................... 50
4.2.1 Methodology ......................................................................................................... 50
4.2.2 Objectives and risk analysis .................................................................................... 51
4.2.3 Elicitation of the requirements and the SRS ........................................................... 52
4.3 Architecture and Modelling ........................................................................................... 57
4.4 General Physical Risk Assessment ................................................................................. 62
4.5 Validation Plan .............................................................................................................. 63
4.6 Validation of the Requirements ..................................................................................... 64
4.7 Results – Discussion ...................................................................................................... 65
5 GAS TURBINE INTERFACING ................................................................................................. 67
5.1 Methodology ................................................................................................................ 67
5.2 Risk Assessment ............................................................................................................ 68
5.3 Analysis, Design and Implementation ............................................................................ 69
5.3.1 Software ................................................................................................................ 69
5.3.2 Hardware ............................................................................................................... 72
5.4 Validation ..................................................................................................................... 73
5.5 Results – Discussion ...................................................................................................... 74
6 ENGINE OPERATION CONTROL SOFTWARE. .......................................................................... 79
6.1 Methodology ................................................................................................................ 79
6.1.1 Approach to the software modules design ............................................................. 79
6.1.2 General test harness .............................................................................................. 81
6.1.3 Validation methodology ......................................................................................... 81
6.2 Risk Assessment ............................................................................................................ 81
6.3 Analysis, Design and Implementation ............................................................................ 82
6.3.1 EIS adaptation ........................................................................................................ 82
6.3.2 EIS Interface ........................................................................................................... 83
6.3.3 MEOCS ................................................................................................................... 85
6.3.4 The General Test Harness....................................................................................... 88
6.4 Validation ..................................................................................................................... 90
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6.5 Results – Discussion ...................................................................................................... 91
7 ADDITIONAL FEATURES ........................................................................................................ 97
7.1 Methodology ................................................................................................................ 97
7.1.1 Ambient parameters and mains power supply – Live image ................................... 97
7.1.2 Peripheral features ................................................................................................ 98
7.1.3 The Trouble Shooting System module (TSS)............................................................ 99
7.1.4 Validation Methodology ....................................................................................... 101
7.2 Risk Assessment .......................................................................................................... 101
7.3 Analysis, Design and Implementation .......................................................................... 102
7.3.1 The ACAS – Addition of other modules and adaptations ....................................... 102
7.3.2 Peripheral Hardware ............................................................................................ 109
7.3.3 The Troubleshooting System (TSS) ....................................................................... 110
7.4 Validation ................................................................................................................... 118
7.5 Results – Discussion .................................................................................................... 119
8 INTERNET IMPLEMENTATION ............................................................................................. 130
8.1 Methodology .............................................................................................................. 130
8.1.1 Host website and web applications ...................................................................... 130
8.1.2 Service invocation ................................................................................................ 132
8.1.3 User Interface and live video transmission ........................................................... 133
8.1.4 Security of the application ................................................................................... 134
8.1.5 Validation methodology ....................................................................................... 135
8.2 Risk Assessment .......................................................................................................... 135
8.3 Analysis, Design and Implementation .......................................................................... 136
8.3.1 The host website. ................................................................................................. 136
8.3.2 The main web application .................................................................................... 139
8.3.3 Functionality and the REST API ............................................................................. 141
8.3.4 Adaptations of existing modules .......................................................................... 145
8.3.5 The operation panel web page ............................................................................. 150
8.3.6 Additional Functionality ....................................................................................... 150
8.4 Validation ................................................................................................................... 151
8.5 Results, Discussion ...................................................................................................... 152
9 ACCEPTANCE VALIDATION.................................................................................................. 159
9.1 Objectives – Risk Assessment ...................................................................................... 159
9.2 Methodology .............................................................................................................. 160
9.2.1 Requirements testing and final testing methodology ........................................... 160
9.2.2 Probabilistic analysis methodology....................................................................... 162
9.3 Requirements testing and final testing ........................................................................ 167
9.4 Probabilistic analysis of reliability ................................................................................ 169
9.5 Results – discussion..................................................................................................... 174
10 DEVELOPMENT CAPABILITIES ........................................................................................... 178
10.1 Addition of different gas turbines .............................................................................. 178
10.2 Configuration with multiple test stations and gas turbines ........................................ 180
10.3 Integration with the WebEngine................................................................................ 186
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10.4 Practical Applications ................................................................................................ 191
11 RESULTS - DISCUSSION ..................................................................................................... 193
11.1 SRS – General risk assessment ................................................................................... 193
11.2 Implementation ........................................................................................................ 193
11.2.1 Round 1 ............................................................................................................. 193
11.2.2 Round 2 ............................................................................................................. 194
11.2.3 Round 3 ............................................................................................................. 194
11.2.4 Round 4 ............................................................................................................. 195
11.3 Validation ................................................................................................................. 196
11.4 Installation and data handling ................................................................................... 197
11.5 Optimisation of different aspects of the application .................................................. 199
12 CONCLUSIONS - RECOMMENDATIONS FOR FURTHER WORK ............................................ 202
12.1 Conclusions ............................................................................................................... 202
12.1.1 Risk mitigation ................................................................................................... 202
12.1.2 Quality factors ................................................................................................... 204
12.1.3 Reusability ......................................................................................................... 208
12.2 Future work .............................................................................................................. 208
REFERENCES ......................................................................................................................... 213
APPENDICES .......................................................................................................................... 224
Appendix A Functional Requirements ............................................................................... 224
Appendix B Risk Assessment ............................................................................................. 243
Appendix C Software Components Control Flow Validation .............................................. 271
Appendix D Acceptance and Final Validation ..................................................................... 307
Appendix E Software Components Documentation ........................................................... 343
Appendix F Installation Guidelines .................................................................................... 383

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