Finding an optimal shape of a high-speed train requires a thorough understanding of the surrounding flow when the train is affected by cross-winds. Stationary winds can be strong but they are easier to predict and their effect can be reduced through e.g. speed reduction of the train. Wind gusts which occur when the train leaves a tunnel or other obstacle, on a bridge or an embankment are often more dangerous for the security of the train. The existing knowledge about the influence of the wind gusts is very limited due to the difficulties to study these in experiments (in wind tunnels).

We are using our numerical methods, detached eddy simulation (DES) to study this flow. The goal of the proposed project is to create a thorough understanding of the influence of the train's shape on its stability in wind gusts and to suggest recommendations for design of high-speed trains. We shall suggest the modifications of design of high-speed trains that are needed for good cross-wind stability. Besides, the project will find the most dangerous flow conditions (yaw angle, wind and train velocity etc.) which can be used by Banverket to give recommendations about speed limits or wind barriers on the parts of the track that are especially influenced by wind gusts.
 

1. S. Krajnovic, "Novel development in numerical simulations for aerodynamics of high-speed trains", In Proceedings of the 20th Nordic Seminar on Computational Mechanics, November 23-24, 2007, Gothenburg, Sweden View PDF file
    
   
2. Krajnovic S., Numerical Simulation of the Flow Around an ICE2 Train Under the Influence of a Wind Gust, "International Conference on Railway Engineering 2008 (IET ICRE2008)", Challenges for Railway Transportation in Information Age, 25-28 March, 2008, Hong Kong, China