An Optimized Wind-Tunnel Methodology for Realistic Aerodynamic Investigations of Freight-Trains

Kurzfassung

A wind-tunnel methodology has been developed to improve the accuracy when predicting aerodynamic forces– important for operational efficiency and safety– through more representative modelling of real-world conditions. Measurements taken rail-side in field experiments of the surface-pressure, derived global forces and moments, and the boundary layers around operational freight-trains were used to optimize and subsequently validate the wind-tunnel methodology. The resulting methodology employs boundary layer augmentation– additional surface roughness using spires and Lego blocks– as well as detailed under-body and wagon geometries to achieve similar coefficients of drag, average and fluctuating surface pressure magnitude and surface boundary layers as observed in the real-world.