Experimental investigation of the aerodynamics of a class 43 high speed train

630 Pages·2017·35.53 MB·English

by  Martin Gallagher

EXPERIMENTAL INVESTIGATION
OF THE AERODYNAMICS OF A
CLASS 43 HIGH SPEED TRAIN

Martin Gallagher

A thesis submitted to the University of Birmingham for the degree of
DOCTOR OF PHILOSOPHY

School of Civil Engineering
College of Engineering and Physical Sciences
University of Birmingham
B15 2TT
23rd September 2016
University of Birmingham Research Archive

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Abstract

ABSTRACT

This study aims to investigate the aerodynamic phenomena of passenger trains by undertaking
a series of experimental investigations into the aerodynamics of a Class 43 high speed train
(HST). A contextual research background is presented with regards to two significant
aerodynamic pheoneona - slipstreams and crosswinds. Model scale experiments were
undertaken on a 1/25th scale HST model at the transient aerodynamic investigations (TRAIN)
rig moving model rig facility in order to measure slipstreams at a range of trackside positions
and with different ballast heights. Crosswind effects were investigated through two model-
scale tests and an extensive campaign of innovative train-based surface pressure
measurements onboard an operational HST. A wind tunnel test investigated the flow field and
pressure distribution around an HST power car and calculation of aerodynamic loads. A
symmetrical pair of pressure taps at the train nose enabled yaw angle to be calculated at full
scale. A scale-model test using a crosswind generator was undertaken and the magnitudes of
aerodynamic loads compared very favourably with the wind tunnel data. The novel full scale
it has been possible it isolate open-air data and gusts, and estimate the overturning forces due
to crosswinds by a considered approach to surface pressure measurements.

Acknowledgements

ACKNOWLEDGEMENTS

I begin and thanking both of my academic supervisors, Professor Chris Baker and Dr Andrew
Quinn. It has been both a pleasure and a privilege to work with both of you and your
combined knowledge on the fascinating study of train aerodynamics and continued input
throughout this study has been invaluable.
Thanks are given to the EPSRC for funding of the project "The measurement of train
aerodynamic phenomena under operational conditions". This project was most certainly a
team effort, and I would like to thank all of the academics and staff involved, as well as the
industry stakeholders in this project - Network Rail, Railway Safety and Standards Board and
Mott Macdonald. Thanks to Professor Mark Sterling and Dr Hassan Hemida for the valuable
contributions made throughout the project, and in particular for the advice and feedback given
during annual reviews. I would like to thank former TRAIN rig manager Dr Sarah Jordan for
her ongoing optimism and valuable help with the experimental campaigns - such as teaching
me how to use and cope with the TRAIN rig, drilling holes and sticking things on a rather
important New Measurement Train, and with setting up the full scale slipstream measurement
system, organising the trip and sharing in the dismay of their cancellation. I must also thank
the new TRAIN rig manager Dr David Soper for his help undertaking almost the entirety of
the TRAIN rig tests, his uncanny ability to fix any problem at the TRAIN rig in a more
sophisticated manner than just "hitting it with a hammer", and also his advice on treating
model scale data with caution - "if it seems to be real, it's an illusion".
Acknowledgements

With regards to the full scale train based measurements on the NMT, I would like to thank Dr
John Easton and Rhys Davies (and numerous other members of the electrical engineering
team) for designing the data acquisition hardware and software that made analysing the NMT
data much more simple and straightforward, and also for designing a system robust enough to
last almost 3 years. Additionally, Ed Steward and Paul Weston deserve thanks for their help in
installation of the system and calibration of the equipment. Dr Andrew Quinn deserves a
second mention for being the mastermind behind the NMT tests.
Specific thanks to Terry Johnson from RSSB for his continued input and interest throughout
the project and suggestions for experimental work. Mr Steve Burrows from Network Rail who
facilitated visits to the NMT, and also the train technicians from RVEL, Simon, Peter and
Steve who took time away from their busy schedules to supervise and assist during any
inspections and maintenance work on the NMT.
I would like to also thank my other academic colleagues - Dominic Flynn, Tim Gilbert,
Matthew Haines, Francesco Dorigatti, Adam Jackson and Justin Morden. The many
conversations and suggestions made during this project, as well as helping with experiments
and research were invaluable. In particular I would like to thank Justin who undertook a
project in parallel with this one, and was a great help with setting up the full scale
experiments and also for his help with the model scale tests at the TRAIN rig. I would also
like to thank the two students who helped me undertake tests at the TRAIN rig - Charlène and
Aleks.
I would like to thank Derwent Patterns Ltd were responsible for constructing the TRAIN rig
model and various ballast shoulders for the slipstream experiments, and Mike Vanderstam in
the civil engineering laboratories for helping with the wind tunnel work.
Acknowledgements

Finally, I would like to thank my friends and family for their support, advice and love. My
brothers and sisters - Joe, Kirstie, Maria and Steven, and of course most of all my parents -
you've all been supportive and have (at the very least pretended to) taken an interest in this
work, and for that I am grateful.

Contents

CONTENTS

Chapter 1 - Introduction ......................................................................................................... 1
1.1 Outline of this study .......................................................................................................... 1
1.2 Research background ........................................................................................................ 2
1.2.1 High speed rail in the UK ........................................................................................... 2
1.2.2 The Class 43 HST ....................................................................................................... 3
1.2.3 Aerodynamic phenomena - slipstreams ...................................................................... 5
1.2.4 Aerodynamic phenomena - crosswinds ...................................................................... 6
1.3 Motivation ......................................................................................................................... 7
1.4 Research aim and objectives ............................................................................................. 9
1.5 Structure of thesis ........................................................................................................... 10

Chapter 2 - Literature review ............................................................................................... 15
2.1 Introduction ..................................................................................................................... 15
2.2 Preliminary definitions of fluid motion .......................................................................... 16
2.2.1 Definition of Cartesian axes and velocity vector components .................................. 16
2.2.2 Normalised velocity and pressure ............................................................................. 18
2.2.3 Turbulence intensity and ensemble averaging .......................................................... 19
2.2.4 Integral length and time scales .................................................................................. 21
2.2.5 Boundary layer equations ......................................................................................... 22
2.2.6 Strouhal number ........................................................................................................ 24
2.3 Slipstreams and pressure transients ................................................................................ 24
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