The effect of wind tunnel size and shock strength on incident shock boundary layer interaction experiments

We computationally examine the effects of varying the tunnel width to height ratio, the incident shock strength, Mach number, and boundary thickness on the shock boundary layer interaction of an incident oblique shock with a turbulent boundary layer. The computational domain is a simplified representation of typical wind tunnel experiments; the top wall of the tunnel is not modeled; only the flow conditions imposed by the shock are modeled on the top of the computational domain. We compare the sizes of the flow separation zone on the tunnel centerline resulting from the variation of the tunnel sizes and shock strengths with a conjecture of the expected effect of width to height ratio. The flows are found to be three dimensional for the range of shock strengths and width to height ratios considered. The effect of tunnel width on the separation is a function of increasing boundary layer thickness which decreases the effective width. We show that the effect of shock strength and Mach number on separation length can be collapsed into a single curve by proper scaling.