横風を受ける在来線パンタグラフの揚力特性に関する数値流体解析

抄録

Aerodynamic characteristics of a conventional line pantograph under a crosswind are investigated by conducting large-eddy simulation (LES). In our previous study, wind tunnel tests using a full-scaled pantograph were carried out at various attack angles of the crosswind and at various traveling directions of a pantograph to understand the lift force characteristics of a pantograph under crosswind condition. These experiments find that the lift force is significantly increased when the yaw angle is set to 56 deg., however, the mechanism of increment of the lift force has not been clarified. Therefore, in this study, we investigated a flow field around the pantograph head and the lift force characteristics on one of crosswind conditions (roll = 15 deg. and yaw = 56 deg.) at which a high lift force is calculated to occur by using LES. The computational results of the LES are validated by comparing pressure coefficient distribution around the pantograph head with the results of the experiment. From the computational results, it is suggested that one pantograph head located in upstream produced about three times as much lift as the other pantograph head located in downstream. This is mainly caused by the high suction peak of the pressure coefficient over the upper surface and higher pressure over the lower surface of the upstream pantograph head. From the flow field analysis, it is suggested that this suction peak is due to the stational large-scale vortex which is generated over the upper surface of the pantograph head.