Experimental Investigation of Three-Dimensional Vortex-Airfoil Interaction in ASupersonic Stream

摘要

An experimental study of the interaction between stream-wise vortices and a two-dimensional surface was conducted in a Mach 2.5 flow. The influence of oblique shock wave intensity on the inherently three-dimensional interaction was examined for vortices of variable strength. Planar laser sheet visualizations of the flowfield generated by the interaction at several distances downstream of the wedge leading edge were performed in order to gain an understanding of vortex behavior at distances further downstream. Results indicated that the interaction of a moderate strength vortex with an oblique shock wave leads to the formation of a steady separated shock structure upstream of the oblique shock front. Planar laser sheet visualization of the flowfield revealed an expansion of the vortex core in crossing a strong oblique shock front. The vortical structure was observed to persist along the entire chord of the shock generating wedge but was seen to diffuse with distances downstream of the wedge leading edge. Measurements of the vortex center above the wedge surface indicated that immediately downstream of the normal portion of the bulged-forward shock wave the vortex center was parallel to the direction of the free stream flow. (AN).