An Experimental Study on Bow Shock Wave/Turbulent Boundary Layer Interaction Region Induced by Blunt Body

摘要

Bow shock wave/turbulent boundary layer interaction regions induced by a blunt body have been experimentally investigated carefully. Experiments have been performed under the testing condition of free-stream Mach number of 3.8, total pressure of 1.2 MPa and Reynolds number of 2.8 X10~7 with almost adiabatic wall condition. By selecting the displacement h, between a flat plate and a blunt body simulating Solid Rocket Booster (SRB), as the main parameter, the effects of the displacement on the flowfields are examined. First of all, flowfields are visualized by use of the Schlieren method, and surface flows are visualized by oil flow technique, then surface pressure distributions are measured for various h, 5, 10, 15 and 20 mm. For small h, the secondary separation with the primary separation is observed, and there exists a new weak separation downstream of the attachment line. On the contrary for large h, no secondary separation is observed, and the flow structure becomes much simple. The results show that the peak pressure is rapidly decreased as h is increased, also as apart from the centerline. Clearly the displacement affects the interaction region considerably. Those detailed flow structures are revealed.