Plenoptic PIV Applied to 3D Single-Fin SBLI With and Without Flow Actuation*

Plenoptic particle image velocimetry (PIV) was performed to obtain direct 3D measurements of a shock wave-boundary layer interaction (SBLI) generated by a single unswept fin. The experiments were conducted for the SBLI with and without the influence of flow actuation in order to determine the response of the flowfield. The fin was placed at an angle of attack of 15° in Mach 2 flow to generate a 45° oblique shock, which interacts with the boundary layer on the tunnel floor. The volumetric PIV elucidates aspects of the flowfield that have not been considered in 2D studies for this type of SBLI. In particular, how the fin influences the flow, the 3D behavior of the oblique shock as it propagates from the fin apex, and how the flow actuation effects the overall flowfield. The mean flowfield response of the SBLI to actuation is not drastic, which is expected since the actuators used are pulsed at high frequency, but there are slight differences observed. The 3D plenoptic results are also compared to stereoscopic PIV results to highlight aspects that are not able to be seen using 2D visualization techniques.