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