Aerodynamics of Freight Trains – Addressing the Complexity of Train Geometry through an Open Database

The study of the aerodynamics of freight trains is important for safety, efficiency and reducing damage during the operation of freight trains. It is also very important for the accurate estimation of drag resistance and, correspondingly, of the required traction effort. Computational fluid dynamics (CFD) is often used to investigate air flows around a freight train and their effects on vehicle dynamics, especially on drag, slipstream and pressure pulses in tunnels. Most of these studies, however, considered container wagons, while a much wider variety of wagon types are currently used. Therefore, there is a need for further research investigating the aerodynamics of more freight train geometries. This involves intensive work investigating realistic wagon geometries and generating representative generic versions. Subsequently, a complex freight train can be generated from these generic building blocks. To address the need for efficient production of these consists, a database of representative wagon and locomotive geometries was created. In this work, the geometry database is presented and is used to generate realistic freight train geometries suitable for CFD analyses. Then, selected results of CFD simulations performed using the geometries generated from the database are presented, demonstrating the use of the tool.