Single Camera 3D Measurement of a Shock Wave-Turbulent Boundary Layer Interaction

Abstract

This paper explores the 3D structure of an unswept fin generated shock wave-turbulent boundary layer interaction (SBLI). A Mach 2 flow encounters an unswept fin at an angle of attack of 15 degrees which causes an inviscid, oblique shock wave with a wave angle of approximately 45 degrees. The oblique shock wave introduced by the fin interacts with the turbulent boundary layer along the bottom surface. This interaction causes flow separation, and forms a lambda-shaped shock structure. This structure has been studied extensively in quasi-2D representations, but the fully 3D structure has not been studied previously. A plenoptic camera is a unique diagnostic tool that captures 3D information using a single camera. This novel imaging system can be combined with particle image velocimetry to obtain 3D velocity data about a flow field. This work is the first application of a plenoptic camera for volumetric studies of SBLI, and it has proven the unique capabilities of the plenoptic camera to obtain 3D velocity information in areas of limited optical access and in supersonic flows. Comparison with stereo PIV data and inviscid shock theory show a good agreement.