Shock-Boundary Layer Interaction due to a Sharp Unswept Fin in a Mach 2 Flow

Volumetric Measurement of a Shock Wave-Turbulent Boundary Layer Interaction Using Plenoptic Particle Image Velocimetry

“…The relaxation time (τ p ) was suggested by Melling 20 as a measure of the particle's ability to respond to the fluctuations in a flow. Arora et al 6 previously found the relaxation time of the particles used in these experiments to be 1 µs. Ragni et al 21 reported common relaxation times to be 2 µs to 3 µs.…”

“…The inception zone and the inherent strength of these interactions leads the VCO to shift slightly forward of the fin apex. The previous planar PIV study 6 was performed on two separate planes at distances of 0.5L and 0.66L away from the edge of the fin, where L is the fin length (L = 76.2 mm). These two planes were chosen to demonstrate the 3D nature of the interaction, and to show the conical symmetry.…”

“…Due to the experimental setup, it was necessary to extract slices of the velocity field at a 45 degree angle rotated about the y axis. This extraction was done in order to align the planes normal to the shock wave as in the experimental setup of Arora et al 6 The U velocity contours are shown in Figure 7a and 7b. Due to the conical symmetry of the interaction structure, certain features were expected from the plenoptic PIV results: the growth of the separation bubble with increased distance from the fin apex, the increase in the distance between the separation shock and the triple point, and the triple point rise in the y direction.…”

“…This figure is from a previous study in the same facility and geometry. 6 The incoming flow is at Mach 2, and the fin is set at a 15 • angle of attack. This results in a planar oblique shock wave at an angle of 45 • with respect to the free stream.…”

“…In their study, planar PIV was performed at different planes along the shock wave in order to determine the change in the interaction features at various spanwise distances. In addition, Arora et al 6 used a similar technique to perform planar PIV on an unswept fin SBLI. In this study, planar PIV was performed on planes normal to the shock wave and at different depths away from the fin apex.…”