ABSTRACT
The aerodynamic drag of railway vehicles tends to increase as the vehicle speed elevates. When trains are crossing each other, passing through a tunnel or passing through a windy area, the aerodynamic load on railway vehicles will increase dramatically. The increased aerodynamic load influences the dynamics of railway vehicles, which can compromise vehicle passenger comfort and poses a potential threat to vehicle safety. This chapter begins with the definition of vehicle aerodynamics and details the corresponding terminologies. The chapter then introduces the study methods related to vehicle aerodynamics, including numerical simulations, wind tunnel tests, moving-model tests and real-car experiments with respect to each method’s basic principles and scope of applications. The characteristics of the exterior flow field of railway vehicles is analysed and key influential factors on railway aerodynamics, such as vehicle shape, road condition, tunnel structure and wind speed, are analysed with respect to their effects on aerodynamic loads of railway vehicles. Representative aerodynamic loads for operating vehicles, such as drag force, lift force, side force and corresponding moments, are given as a stimulus to vehicle dynamics. The assessment standards for railway aerodynamic loads are given, serving as a basis for the study of vehicle dynamics.
