Effect of flow three dimensionality on interaction length in shockwave turbulent boundary layer interaction

Shockwave boundary layer interaction (SBLI) is a complex flow phenomenon that is important in many practical situations. Shockwave of particular strength can cause flow separation which can change the pressure distribution on the wall. Our current understanding of shockwave boundary layer interaction is based on experimental and numerical work using two-dimensional canonical geometries. Whereas, in most of the aerodynamic flow situations such as flow on control surfaces of the aircraft, flare separations, and supersonic intakes, the flow is three dimensional. For the current study, experiments were performed using multiple two-dimensional shock generators with different widths, in a Mach 2.0 wind tunnel. As the shockwave generator is not occupying the full width of the tunnel, the incident shockwave would become a more three-dimensional shock when it interacts with the bottom wall. It was found that the incident shockwave curves downstream in both side and top views, the shock strength decreases at the impingement location, changing the structure of SBLI. Three dimensionality was found to decrease the tendency to separate, by decreasing the local shock strength near impingement. It was also noted that the shock strengths were different for the two dimensional and three-dimensional shocks even though their wave angles were the same.