Aerodynamic Performance of a Typical High-Speed Train

Abstract:- This paper presents results of wind tunnel experiments on the aerodynamic performance of a generic high-speed train. The wind tunnel model used is a simplified 1:10 scaled ICE21. This so-called “Aerodynamic Train Model ” (ATM) is Bombardiers standard train geometry for the validation of numerical simulation methods and for the comparison of results obtained in different wind tunnels. Attention is confined to the aerodynamic loads on the first car of the ATM when exposed to a range of yaw angles (-30°<β<60°). Flow speed was varied in the experiment from 30 to 70m/s, which corresponds to Reynolds numbers of Re = 0.6~1.4·106 based on the approximate model width of 0.3 m. The focal points of the investigation are wind tunnel experiments performed in the open wind tunnel T103 of the Central Aerodynamic Institute TsAGI. Experimental results are reported for integral forces and moments, surface pressure and the velocity field in regions near to the train model. Comparisons are made with regards to different levels of geometric complexity, addressing the issue of bogies and spoilers. An internal six-component strain-gauge balance was used for measuring the aerodynamic forces and moments acting on the leading car model in the presence of an end car model and non-moving ground. A pressure-scanning system and rake with 7-hole pressure probes were used for measuring the pressure distribution and velocity field, respectively. The experimental data have been generated primarily for the validation of numerical simulation models used within Bombardier. The data has also deepened the understanding of basic flow physics of slender body aerodynamics in the presence of ground