A numerical study of crosswind effects on the slipstream of a freight train

When a train moves through the air it generates a region of moving air which is known as the 'slipstream'. Numerical simulations were conducted of the slipstream around a model-scale freight train when subjected to crosswinds with two different yaw angles relative to the train of 10 and 30 degrees. The results were compared with results obtained from a previous slipstream study on the same train but without a crosswind. For both crosswind cases, significant slipstream amplification was observed with velocity peaks around the locomotive exceed the train speed. Massive velocity transients occurred on the leeward side of the train in the 30 degree case which were a result of flow passing through the inter-wagon spacings. The slipstream velocities measured on the leeward side of a high speed passenger train were compared with the present freight train study. It was found that despite the freight train case being subjected to a lower speed crosswind, the velocities produced on the leeward side were still greater than those from the passenger train case which experienced a higher speed crosswind.