The Aerodynamics of a Container Freight Train

320 Pages·2016·0.52 MB·English

by  David Soper (auth.)

Springer Theses
Recognizing Outstanding Ph.D. Research
David Soper

The Aerodynamics
of a Container
Freight Train
Springer Theses
Recognizing Outstanding Ph.D. Research
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David Soper
The Aerodynamics
of a Container Freight Train
Doctoral Thesis accepted by
the University of Birmingham, UK
123
Author Supervisors
Dr. DavidSoper Prof. Chris Baker
Schoolof Civil Engineering Schoolof Engineering
University of Birmingham University of Birmingham
Birmingham Birmingham
UK UK
Prof. Mark Sterling
Schoolof Engineering
University of Birmingham
Birmingham
UK
ISSN 2190-5053 ISSN 2190-5061 (electronic)
SpringerTheses
ISBN978-3-319-33277-2 ISBN978-3-319-33279-6 (eBook)
DOI 10.1007/978-3-319-33279-6
LibraryofCongressControlNumber:2016937512
©SpringerInternationalPublishingSwitzerland2016
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Publications
SincecompletingthisPh.D.theauthorhaspublishedinaseriesofjournalpaperson
various parts of the thesis. This section provides a list of these publications and
those related to the work carried out within this thesis.
David Soper, Chris Baker, Mark Sterling. Experimental investigation of the slip-
streamdevelopmentaroundacontainerfreighttrainusingamovingmodelfacility.
Journal of Wind Engineering and Industrial Aerodynamics, Volume 135, Pages
105–117, 2014.
David Soper, Chris Baker, Mark Sterling. An experimental investigation to assess
the influence of container loading configuration on the effects of a crosswind on a
container freighttrain. Journal ofWind EngineeringandIndustrialAerodynamics.
Accepted for publication, 2015.
Dominic Flynn, Hassan Hemida, David Soper, Chris Baker. Detached-eddy sim-
ulation of the slipstream of an operational freight train. Journal of Wind
Engineering and Industrial Aerodynamics, Volume 132, Pages 1–12, 2014.
The first paper presents the results relating to the model-scale slipstream
experiments discussed in Chap. 4. The paper focuses on a cross section of the
container loading configurations discussed in this thesis, drawing simple conclu-
sions on the effect of reducing the container loading efficiency. The second paper
contains the results for aerodynamic loads measured within a crosswind, as pre-
sented in Chap. 7. Similar to the first paper, the second paper focuses on a cross
section of container loading configurations to explore the effects of reducing con-
tainer loading efficiency. The third paper presents a comparison of model-scale
experimental data with results from a CFD simulation. The model-scale data was
used as a point of validation for the CFD study.
An additional consultancy project outside of the main context of the research
presentedinthisstudy,carriedoutbytheauthorduringhisPh.D.,wasdiscussedin
Chap.1.Thefindingsfromthisprojecthavenowbeenpublishedintwoconference
journal papers:
Richard Sturt, Chris Baker, David Soper, Alan Vardy, Mark Howard, Colin
Rawlings. The design of HS2 tunnel entrance hoods to prevent sonic booms. 13th
International Conference & Exhibition on Railway Engineering, Edinburgh, UK,
2015.
Alan Vardy, Richard Sturt, Chris Baker, David Soper. The behaviour of long
entrance hoods for high speed rail tunnels. 16th International Symposium on
Aerodynamics, Ventilation and Fire in Tunnels, Seattle, USA, 2015.
’
Supervisors Foreword
The UK rail freight industry is a growing sector with increasing volumes of
internationaltradefromnewcontractsforfreightthroughtheChannelTunnel.The
increasingvolumeoffreighttradehasledtoproposedrisesinfreighttrainspeedsto
help manage the additional traffic within an already congested rail network.
The airflow around a moving vehicle is called a slipstream, characterised by a
highlyturbulentnon-stationaryregionofair.Inducedslipstreamforcescaninteract
with trackside objects, potentially destabilisingsuchobjectsandpeople.Thereisa
real concern that the unsteady slipstream created around a moving freight train
could have implications on efficiency and the safety of passengers waiting on
platforms or trackside workers. Similarly, transient airflows created by vehicle
movementwhen coupled with naturallyturbulent crosswindscancreatea series of
steady and unsteady aerodynamic forces and moments, potentially inducing sig-
nificant changes to vehicle dynamic behaviour and compromising stability.
Between 2008 and 2015 there have been multiple incidents in the UK of freight
containers blown from trains in strong gusty wind conditions.
The need for interoperability for rail operators across Europe has led to the
development of the Technical Specifications for Interoperability (TSI); a series of
regulations which include safety limits for train aerodynamics. Safety limits are
calculated within a set of guidelines. However, in many cases there is a lack of
research into the airflow created by different train types, which raises questions
about the suitability of the TSI limits, where European homologation is a
requirement.
The research carried out by Dr. David Soper aims to characterise the aerody-
namic flow around a container freight train and investigate how changing the
container loading configuration affects the magnitude of aerodynamic forces mea-
sured on a container. Experimental data, from novel model and full-scale studies,
hasledtoanin-depthunderstandingoftheaerodynamicflowdevelopmentarounda
container freight train through measuring slipstream velocities and static pressures
for a series of measuring positions and different container loading configurations.
Theaerodynamic loads onacontainer mountedtoamovingmodel trainwerealso
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viii Supervisors’Foreword
measuredforbothcrosswindandnon-crosswindconditions,tohelpunderstandthe
differenceinoverturningforcemagnitudesincrosswindconditions.Theauthorhas
also shown large differences occur in the aerodynamic flow development around a
container freight train in comparison to a high-speed passenger train, raising
questionsabout whether theEuropeanTSIregulationsarenecessarilyadequatefor
freight trains.
The knowledge from this study forms an important basis for further studies on
freighttrains,alongsideknowledgealreadygatheredonhigh-speed passengertrain
studies, to help increase the efficiency and safety of rail transportation in the UK
and throughout the world.
Birmingham, UK Prof. Chris Baker
July 2015 Prof. Mark Sterling
Abstract
Thisresearchaimstocharacterise theaerodynamicflow around acontainerfreight
train and investigate how changing the container loading configuration affects the
magnitude of aerodynamic forces measured on a container. Experiments were
carried out using a 1/25th scale moving model freight train at the University of
Birmingham’s TRAIN rig facility. The model was designed to enable different
container loading configurations and train lengths to be tested. A series of exper-
iments to measure slipstream velocities and static pressure were undertaken to
assess the influence of container loading configuration. Experiments to measure
aerodynamic loads on a container were carried out using an on-board pressure
monitoring system built into a specifically designed measuring container.
A collation offull-scale freight data from previous studies provided a tool to val-
idate model-scale data.
Analysis offreight data found it was possible to present slipstream results as a
seriesofflowregions.Cleardifferencesinslipstreamdevelopmentandaerodynamic
load coefficients were observed for differing container loading configurations.
Velocity and pressure magnitudes measured in the nose region were larger than
values observed previously. For container loading efficiencies higher than 50 %
boundary layer growth stabilises rapidly, however, for less than 50 % continual
boundary layer growth was observed until after 100m when stabilisation occurs.
Velocities in the lateral and vertical directions have magnitudes larger than previ-
ouslyobserved;increasingtheoverallmagnitudeby*10%.Comparisonofmodel
and full-scale data showed good agreement, indicating Reynolds number inde-
pendence. An analysis of TSI safety limits found results lie close to, but do not
break,existinglimits.Aerodynamicloadcoefficientswerecomparedwithprevious
studies and shown to be characteristic of typical values measured for a 30° yaw
angle; however, differences between static wind tunnel and moving model results
were discovered.
ix
Acknowledgements
I wish to express my gratitude to my supervisors, Profs. Chris J. Baker and Mark
Sterling, for providing me the opportunity to undertake this research and for their
support throughout the study. I have greatly benefitted from their knowledge of
wind engineering and vehicle aerodynamics, drawing upon their experience and
understanding of technical details related to experimental wind engineering.
I would also like to express my sincere gratitude to them for helping me deal with
thehardshipsIencounteredduringthefirstfewmonthsofmystudies.Iwouldlike
to thank Dr. Andrew D. Quinn and Dr. Hassan Hemida for their advice, encour-
agement and valued discussions throughout my studies. Furthermore, I would like
toexpressmysincerethankstoDr.AndrewD.Quinnforallowingmetoutilisethe
freight experimental data from Uffington and for patiently discussing any issues
Iencounteredwhenanalysingthedata.Ifeelfortunatetohavehadtheopportunity
to have been supervised by and to work alongside the team of academics in the
wind engineering group at the University of Birmingham.
I acknowledge the University of Birmingham Centre for Rail Research and
Education for providing financial support during my Ph.D. studies.
There are a number of people that have provided invaluable help and support
during this project. During the time I have spent at the University of Birmingham,
thesepeoplenotonlyhaveprovidedanimportantcontributiontothecompletionof
thisstudybutalsowhosefriendshipIvaluedeeplyandwithoutwhomIwouldnot
havebeenabletoenjoymytimeinBirminghamasmuch.IamthankfultoDr.Tim
Gilbert,Mr.MattHaines,Mr.DominicFlynn,Mr.NaineshPatel,Mr.Martin‘hitit
with a hammer’ Gallagher and Mr. Justin Morden. I am also thankfulto Dr. Sarah
Jordan,whoseknowledgeoftheTRAINrigandeverwillingnesstohaveachatand
put the world to rights has been invaluable, and Dr. Francesco Dorigatti, whose
expertise in the TRAIN rig crosswind generator has proved to be an invaluable
sourceofknowledgeonmanyanoccasion.Iamverygratefultoallthepeoplewho
have spared a day ortwo to assist inthe work carried outat theTRAIN rig and to
Mr.ManiEntezamithe‘creator’oftheon-boarddataloggerutilisedaspartofthis
research. I would like to thank Mr. Mike Vanderstam and the technicians of the
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