不同类型头部外形列车轨侧压力变化规律分析与评估

By using the method of computational fluid dynamics, based on the analysis of basic aerodynamics(such as aerodynamic drag) of trains with four different head surface forms running in open air including bulge-wide, ellipsoid, spindle, and flat-wide types, the research was conducted on the variation of trackside pressure with the change of spatial locations and head surface forms. The results show that when the four types of trains runat 250 km/h in open air, the bulge-wide type has the largest aerodynamic drag, while the spindle type has the smallest aerodynamic drag, witha maximum difference of 7.4%. The maximum peak to peak value of trackside pressure is induced by the bulge-wide type, followed by the ellipsoid and the spindle types, while the flat-wide type is minimal, with a maximum difference of 24.4%. The influence of the longitudinal profile on the variation of trackside pressure is greater than the horizontal profile. The pressure variation induced by the different longitudinal profiles of bulge-wide and flat-wide type above 1.5 m from the top of railis 721.62 Pa and 545.71 Pa respectively, with a difference of 24.4%. The pressure variation induced by different horizontal profiles of the bulge-wide and the ellipsoid type at the same measuring point is 721.62 Pa and 700.44 Pa respectively, with a difference of only 2.9%. The trackside pressure changes induced by the four different head surface forms are reduced with the increase of the height above the top of rail and the lateral distance from the center of the track. The peak to peak value of the measured point pressure variation is within the requirement of EN standard, which is 800 Pa.