A 2-DIMENSIONAL 2ND-ORDER VORTEX PANEL METHOD FOR THE FLOW IN A CROSS-WIND OVER A TRAIN AND OTHER 2-DIMENSIONAL BLUFF-BODIES

Experiments on an idealized train model in a cross-wind at large yaw angles (60-degrees-90-degrees) suggested that the pressure distribution was essentially two-dimensional at locations away from the nose. This implied that the pressure distribution around most of the model at large yaw angles could be predicted by simply scaling the prediction for 90-degrees yaw. A separated flow model based on a two-dimensional second-order vortex panel method using complex variables has thus been developed for the 90-degrees yaw case. The Kutta condition allows the extension of the method to handle asymmetrical bluff bodies and bluff bodies near a wall (such as the train model). The computed pressure distributions around the train model and other two-dimensional bluff bodies agreed very well with experiments.