Physical model of the swept shock wave/boundary-layer interaction flowfield

Abstract

New data are presented on the structure of fin-induced, swept shock/boundary-layer interactions. These data are obtained using a nonintrusive planar laser scattering (PLS) imaging technique. A range of interaction strengths, from barely separated to very strongly separated, is covered for freestream Mach numbers of 3 and 4. These new data, when combined with previous results on the flowfield and interaction "footprint," are sufficient to allow the construction of a physical model for the swept interaction flowfield structure and behavior. This physical model is presented and discussed in terms of six detailed flowfield maps which take advantage of the inherent quasiconical behavior of the class of interactions considered.

Investigation of Three-Dimensional Shock Wave/Turbulent-Boundary-Layer Interaction Initiated by a Single Fin

“…The "jet" turns around the separation vortex and impinges onto the wall near the mean reattachment line R1. At the impingement location, part of the jet penetrates the separation vortex and forms the reverse flow, which is in agreement with the physical model proposed by Alvi and Settles [65] .…”

Quasiconical free interaction between a swept shock and a turbulent boundary layer

“…The flow in the channel between the boundary layer and the slip surface is turned toward the test surface by a series of compressions and expansions (shown as dotted lines) and possibly by a terminal shock. 16 According to Alvi and Settles, 16 wave focusing may give rise to "shocklets" in this curved channel. This channel flow impinges on the test surface, and, in strongly separated interactions, the surface pressure at flow attachment exceeds the downstream inviscid value.…”

“…For further discussion on the evolution of the flowfield with interaction strength, including the appearance of secondary separation, see Ref. 16.…”

“…14 " 16 In fact Alvi and Settles 15 found that the separation shock angle i|; ss can be correlated against M n . This observation notwithstanding, since the separation shock impinges the boundary layer at the upstream influence, it appears that a more appropriate Mach number for correlating i|* ss based on the conical free interaction hypothesis may be the Mach number normal to the upstream influence line is a pressure function with ^=p^p\ being the pressure ratio across the separation shock.…”

High-Speed Magnetohydrodynamic Flow Control Analyses With 3-D Simulations

“…The interaction of the shock with the boundary layer produces the classic 3-D λ-pattern. 34 The two λs from either side of the symmetry plane cross each other in downstream regions, in a complex manner that has been described in Ref. 26 Fluid near the plate traverses in a nearly spanwise direction, and encounters an adverse pressure gradient, shown later in plots of surface pressure.…”