Katsuji Tanemoto

Abstract The aerodynamic characteristics of train/vehicles under cross winds depend on not only the shapes of the vehicles but also those of infrastructures. Accordingly three kinds of wind tunnel tests were made to evaluate the aerodynamic characteristics of typical configurations of the vehicles on typical configurations of infrastructures such as bridges and embankments. The main results obtained from the wind tunnel tests are summarized below. 1. The aerodynamic side force coefficient of the vehicle increases more as the thickness of the bridge girder becomes larger. It also increases more as the roof of the vehicle becomes edgier. 2. The aerodynamic characteristics of the vehicle on the embankment depend on the distribution of the boundary layer on the ground. The aerodynamic side force coefficient of the vehicle on a high embankment is larger than that on a low embankment.

Since train vehicle accidents caused by strong winds sometimes occur in Japan, Japan railway companies requested the Railway Technical Research Institute to promote research and development of preventive measures. To respond to this request, we have investigated aerodynamic forces acting on train vehicles and characteristics of strong winds and proposed several software and hardware preventive measures. This report presents the results of our investigation and the measures adopted in Japan Railway lines.

A method for estimating the aerodynamic drag of a train, particularly the aerodynamic drag of the Shinkansen train, is presented. In addition to the estimation of the aerodynamic drag, the evaluation of the accuracy of the estimate is made in terms of the total resistances to be measured in the open and in a tunnel. As the result, the contributions of the configuration of the Shinkansen train and the type of the track to the total resistance are clarified.