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

Abstract

Previous observations that fin-generated interactions are quasiconical in nature were further confirmed by surface pressure measurements spanning Mach 2.5-3.5, which encompassed unseparated through strongly separated interactions. For strongly separated interactions in which the shock wave is bifurcated into a X.-foot structure, the conical free interaction hypothesis was validated through an appropriate scaling of the far-field surface pressure distribution. The behavior of the \-foot structure, such as the decrease of the slope of the separation shock with interaction strength, was explained by invoking the conical free interaction hypothesis. Through the conical free interaction hypothesis, it was further shown that the triple-shock intersection behaves in a complicated manner with changes in interaction strength.

Incipient separation in shock wave/boundary layer interactions as induced by sharp fin

“…For engineering purposes, Korkegi (1973) Korkegi (1973), or Lu (1989). Their results also show the trend of α i decreasing with increasing Re θ which had been previously discussed in Lu (1993) and Leung and Squire (1995). It may be noted that Leung and Squire's (1995) experimental data confirmed the same trend for α i versus Re θ as in Dou and Deng's theory.…”

“…As the onset or occurrence of flow separation invariably changes the topology of the flow field, one important and critical problem to resolve is how to judge or predict the incipient separation and its underlying flow physics. A typical topology of the surface flow pattern is shown schematically in Fig.2 (Lu, 1993;Settles and Dolling, 1992) for cases of reference. Stanbrook (1960) is probably the first to define and state that incipient separation takes place when the wall limiting streamlines becomes aligning with the inviscid shock wave.…”

Effects of Sidewall Compression and Relaminarization in a Scramjet Inlet

“…This curve is due to the requirement that pressure must be equal across the slip line. Here, the ramp shock is equivalent to a "Mach stem" in two-dimensional Mach reflection [23]. With the sidewall compression, the flow must be compressed more in the region close to the sidewall and this is achieved by a larger curve, which extends further toward the symmetry plane.…”

Relationship Between Intermittent Separation and Vortex Structure in a Three-Dimensional Shock/Boundary-Layer Interaction

“…The incident shock wave is identified as the region of maximum strain. Unlike a truly 2-D interaction, the incident shock is somewhat curved, as has been studied by Alvi and Settles [23], Kubota and Stollery [20], Lu [24], Panaras [25], Wang et al [38], and Knight et al [52]; it does not extend to the sidewall but, rather, it dies out at about one-quarter of the span from the sidewall. This is consistent with the previous observation that the bottom-wall interaction extends only up to about one-quarter of the span.…”

“…The physics of each unit problem in an unconfined configuration (compression ramp and incident oblique SBLIs) have been extensively studied throughout the years by researchers such as Korkegi [7], Adamson and Messiter [17], Zheltovodov [18], Dolling and Clemens [19], Kubota and Stollery [20], and Delery and Dussauge [21,22]; while Alvi and Settles [23], Lu [24], Panaras [25], and Knight et al [26] have studied the swept-shock interaction, corner effects have been studied by Burton and Babinsky [26]. Numerous review papers on the same interactions have also been published [27,28].…”