Turbulent flow over an embedded, rectangular cavity

A numerical, discrete vortex model is developed for flow over an embedded rectangular cavity, with the separation of the shear layer at the leading edge replaced by periodic insertion of point vortices. The results of the vortex model are compared with the data obtained from an experimental investigation carried out at a free stream speed of 6 m/sec past a rectangular cavity of depth, D, equal to 5 cm; a depth-to-width ratio, D/W equal to 1.0 and length-to-depth ratio, L/D, equal to 4.0. The Reynolds numbers based on the cavity depth is approximately 20,000. Mean velocity and turbulent intensity profiles are presented. Evidence of the three-dimensional nature of the flow has been obtained via oil film and tuft flow visualization techniques. Discrepancies between the model predictions and the experimental results are discussed, as are differences between the three-dimensional flow field examined here and previous infinite span, two-dimensional, cavity configurations. Additionally, a mechanism is developed for the inclusion in the vortex model of various initial separation conditions.