Vortex optimisation of slotted tops and cavities of two different open rail wagons

Abstract

This paper reviews work by the Industrial Aerodynamics Group at the Royal Melbourne Institute of Technology (RMIT) in cavity flows relevant to open rail wagons. Past work indicates that the drag of open wagons can be reduced by 20–30%. More recent work suggests that cavities with a depth equal to the streamwise length may be the optimum configuration to generate stable vortices that minimise the perturbation of the external flow and thereby minimise the cavity drag. Increasing the number of cavities from one large cavity to a number of appropriately-proportioned cavities decreased the drag.