The Aerodynamics of a Container Freight Train

Abstract

This research aims to characterise the aerodynamic flow around a container freight train and investigate how changing container loading configuration affects the magnitude of aerodynamic forces measured on a container. 1/25th scale moving-model freight train experiments were carried out at the University of Birmingham's TRAIN rig facility. Slipstream velocities and static pressure were measured to assess the influence of container loading. Aerodynamic loads were measured using a specifically designed on-board pressure monitoring system. A collation of full scale freight data from previous studies provided a tool for validation. Analysis of freight data found slipstream results could be presented as a series of flow regions. Differences in slipstream development and aerodynamic load coefficients were observed for differing container loading configurations. Velocity magnitudes in the nose region were larger than observed previously. Boundary layer growth stabilises rapidly for loading efficiencies greater than 50%, however, for less than 50% continual boundary layer growth was observed until after 100m when stabilisation occurs. Comparison of model and full scale data indicated Reynolds number independence. Analysis of TSI specifications found results lie close to, but do not break, existing limits. Aerodynamic load coefficients were shown to be characteristic of typical values for a 30° yaw angle.