Train Aerodynamics

I have worked in the field of train aerodynamics since my time at the Railway Technical Centre in Derby in the early 1980s, and have carried out research on trains in cross winds, slipstreams, pressure loading, drag etc.. This page contains the following information.

  • Details of the recent book written by myself and colleagues – Train Aerodynamics – Fundamentals and Applications.
  • A list of recent papers in train aerodynamics, of which I was a significant author, together with links to publisher’s sites.
  • Details of recent PhD theses that I have supervised, with links to the University of Birmingham Repository from where they can be downloaded.

The blog category in Train Aerodynamics includes further material and gives space for discussion of issues in this area.

Blog posts

Recent blog posts in this category include

This video investigates if there is a best shape for a train that will minimised he risk of a wind induced overturning accident occurring. More detail is given in the blog post Train crosswind performance – is there best shape?

Train Aerodynamics – fundamentals and applications

A graduate level text book by Chris Baker, Terry Johnson, Dominic Flynn, Hassan Hemida, Andrew Quinn, David Soper and Mark Sterling

Further purchase details can be found here and here.

From the Preface

The book is divided into two parts. Part 1 addresses a range of fundamental aspects (chapters 1 to 6), and Part 2 (chapters 7 to 13) considers a number of practical applications.  The contents of the individual chapters are as follows.

Chapter 1.      The historical context. This gives a brief historical context to the subject of train aerodynamics and how the field has developed over the last two centuries.

Chapter 2.      Fluid mechanics concepts. This chapter sets out a number of fundamental fluid mechanics concepts that will be drawn on in the chapters that follow, at the level of graduate engineers with some fluid mechanics background.

Chapter 3.      Testing techniques. This chapter provides introductions to full scale testing and to physical model testing with wind tunnels and moving model rigs. Data processing is also discussed. 

Chapter 4.      Computational techniques. This chapter presents the basics of computational fluid dynamics (CFD) as applied to train aerodynamics, and also to a range of optimization techniques.

Chapter 5       The flow around trains in the open air. This chapter gives a description of the flow around trains in the open air with and without crosswind. The flow in different regions around the train is described in some detail, mainly drawing on a range of full-scale data. 

Chapter 6.      The flow around trains in tunnels. This chapter discusses the special case of the flow around trains in tunnels, in particular considering the transient pressure waves created by the passing of trains through tunnels.

Chapter 7.      Aerodynamic drag. This chapter describes methods for measuring and predicting train aerodynamic drag; presents a collation of drag data from a wide variety of trains; and discusses methods of drag alleviation.

Chapter 8.      Aerodynamic loads on trackside structures, passing trains and people. This chapter discusses both pressure loading and velocity (slipstream) loading caused by trains; presents methods for load measurement and prediction and considers how these loads can then be applied in the design and risk analysis process.

Chapter 9.      Ballast movement beneath trains. This chapter considers the various mechanisms that cause ballast to move under trains, both aerodynamic and otherwise, and discusses the initiation of motion, ballast rolling and ballast flight. Applications to train authorization and route risk analysis are also discussed. 

Chapter 10.    Aerodynamic effects on pantographs and overhead wire systems. This chapter describes the nature of the overhead line and pantograph system and considers methods for measuring and calculating the various aerodynamic loads within the system.

Chapter 11.    Train overturning in high winds.  This chapter describes the determination of the crosswind forces and moments on trains, the specification of the natural wind and calculation of the accident wind speed. The issues involved in train authorization and route risk assessment are discussed, together with mitigation methods. 

Chapter 12.    Tunnel aerodynamic issues. This chapter considers a range of practical issues that arise when trains pass through tunnels – the effects of pressure waves on the ears; sonic booms at the outlet of long tunnels on high speed lines; aerodynamic drag in tunnels, structural loading and specific problems associated with very long tunnels. 

Chapter 13.    Emerging issues. This chapter presents short introductions to a range of issues that may come to be of significant importance in the future. 

Train aerodynamics papers

The links given below are to the publishers’ web sites, where the abstract can be read and the publication downloaded with the necessary permissions. Alternatively the final pre-publication of many (but not all) of these can be found the Birmingham Electronic Paper Repository here.

C J Baker, A Quinn, M Sima, L Hoefener, R Licciardello, 2013, Full-scale measurement and analysis of train slipstreams and wakes: Part 1 Ensemble averages. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 228, 5, 451-467, Part 2 Gust analysis, Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 228, 5, 468-480

C J Baker, 2013, A framework for the consideration of the effects of crosswinds on trains, Journal of Wind Engineering and Industrial Aerodynamics 123, 130–142

T Gilbert, C J Baker, A D Quinn, 2013, Aerodynamic pressures around high-speed trains: the transition from unconfined to enclosed spaces, Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid 227, 6, 608-621

T Gilbert, C J Baker, A D Quinn, 2013, Gusts caused by high speed trains in confined spaces and tunnels, Journal of wind Engineering and Industrial Aerodynamics, Journal of Wind Engineering and Industrial Aerodynamics 121, 39–48 

 C J Baker, S J Jordan, T Gilbert, M Sterling, A Quinn, T Johnson, J Lane, 2014, Transient aerodynamic pressures and forces on trackside and overhead structures due to passing trains. Part 1 Model scale experiments”, Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid 228 36 – 69, Part 2 Standards applications, Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid, 22836 – 69

D Soper, C J Baker, M Sterling, 2014, Experimental investigation of the slipstream development around a container freight train using a moving model facility, Journal of Wind Engineering and Industrial Aerodynamics 135, 105–117 

F Dorigatti, M Sterling, C J Baker, A D Quinn, 2015, Crosswind effects on the stability of a model passenger train – a comparison of static and moving experiments, Journal of Wind Engineering and Industrial Aerodynamics 138, 36-51 

D Soper, M Gallagher, C Baker , Quinn A, 2017, A model-scale study to assess the influence of ground geometries on aerodynamic flow development around a train, Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit  231, 8, 916-933  

D Soper, C Baker, A Jackson, D Milne, L Le Pen, G Watson, W Powrie, 2017, Full scale measurements of train underbody flows and track forces, Journal of Wind Engineering and Industrial Aerodynamics 169, 251-264 

D Soper, D Flynn, D, C Baker, A Jackson, H Hemida, 2017, A comparison of methods to simulate the aerodynamic flow beneath a high speed train, Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 44

M Gallagher, J Morden, C Baker, D Soper, A Quinn, H Hemida, M Sterling (2018) Trains in crosswinds – comparison of full-scale on-train measurements, physical model tests and CFD calculations, Journal of Wind Engineering and Industrial Aerodynamics 175, 428-444 

C Baker, M Sterling (2018) The calculation of train stability in tornado winds, Journal of Wind Engineering and Industrial Aerodynamics, 176, 158-165

D Soper, C Baker, 2019, A full scale experimental investigation of passenger and freight train aerodynamics, Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit  

Train Aerodynamics PhD theses

From the University of Birmingham Thesis Repository

N Perez Solero (2012) Measurement and analysis of slipstreams for passenger trains

T Gilbert (2014) Aerodynamic effect of high speed trains in confined spaces

D Soper (2014) The aerodynamics of a container freight train

D. Flynn (2015) A numerical investigation of the effect of crosswinds on the slipstream of a model-scale freight train and associated effects

J. Morden (2017) A numerical investigation of the effects of crosswinds upon the aerodynamic characteristics of a high-speed passenger train and its slipstream

M Gallagher (2017) Experimental investigation of the aerodynamics of a class 43 high speed train