Methods of Calculating Aerodynamic Force on a Vehicle Subject to Turbulent Crosswinds

Abstract

This study compares two methods for calculating the unsteady aerodynamic side force on a high speed train running in a turbulent crosswind at discrete points along a straight track: the method of aerodynamic weighting function, and that of the quasi-steady theory. Both methods are concerned with time series estimation of aerodynamic loading based on experimentally measured crosswind data. By vary ing the mean wind speed, the train speed, and the distance between the simu lation points it is shown that the aerodynamic weighting function approach may be mo re appropriate for estimat ing the unsteady force on a high speed train. The advantage of the weighting function is consideration for the loss of turbulent velocity cross-correlations over the surface of the vehicle in contrast to the quasi-steady approach.