Aerodynamic characteristics of high speed train under turbulent cross winds: A numerical investigation using unsteady-RANS method

Asress Biadgo,Jelena Svorcan,Aleksandar Simonovic,Slobodan Stupar

doi:10.5937/fmet1401010b

Abstract

Increasing velocity combined with reduced mass of modern high speed trains poses the question of influence of strong cross winds on its aerodynamics. Strong cross winds may affect the running stability of high speed trains via the amplified aerodynamic forces and moments. In this study, simulations of turbulent cross wind flows over the leading and end car of ICE-2 high speed train have been performed at different yaw angles The train aerodynamic problems are closely associated with the flows occurring around train. The flow around the train has been considered as incompressible and was obtained by solving the incompressible form of the unsteady Reynolds-Averaged Navier-Stokes (RANS) equations combined with the realizable k-epsilon turbulence model. Important aerodynamic coefficients such as the side force and rolling moment coefficients have been calculated for yaw angles ranging from -30° to 60° and compared to results obtained from wind tunnel tests. The dependence of the flow structure on yaw angle has also been presented.

Highlights

IntroductionThe Ethiopian government has given the Ethiopian Railways Corporation (ERC) the task of developing a national railway network
AND MOTIVATIONRailway transport is widely used in many countries
For large yaw angles, large flow separation zone and lower pressure region exist on the leeward side of the train

Summary

Introduction

The Ethiopian government has given the Ethiopian Railways Corporation (ERC) the task of developing a national railway network. To date Ethiopia has rail transport system which consists of only 781km of old French-built railway from the Red Sea port Djibouti to Addis Ababa. This old French built railway is currently under construction to be replaced by a Chinese-built standard gauge electrified railway. The Ethiopian government has considered constructing a series of eight rail network corridors (Fig.1) totalling 4,744km in two phases, with the aim of creating a series of key trade routes to neighbouring Kenya, South Sudan, Sudan and Djibouti. The construction of railway is a key component of the Ethiopia’s government plan to boost economic growth and enhance regional integration

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