Experimental And Numerical Investigation Of Shock Wave/Boundary Layer Interaction In Hypersonic Flow

Shock wave/boundary layer interaction(SWBLI) is an important phenomenon in hypersonic air-breathing vehicles, which may cause not only harmful flow of no uniformity, total pressure loss, inlet unstart etc., but also bring about severe heat loads which may be far beyond the capability of predictions.In present thesis, some basic physical configurations and two kinds of hypersonic inlet are tested to investigate the SWBLI behaviors with experimental and numerical methods. Structure of shock waves and flow phenomenon close to the surface of the model are observed and pressure, shear stress and heat flux over the surface are analyzed. Furthermore, effect of flow control technology to weaken viscous separation is also evaluated. Some experimental results of shock wave/shock wave interaction are also analyzed.The main results of present work are:1, Results of two dimensional basic figures show the behaviors of SWBLI would change with grown strength of the shock wave. For the case of oblique shock wave impinges on the plate, blowing method was tested to weaken the separation caused by the SWBLI. Groups of data from numerical simulation were analyzed to show how flow phenomenon change with different total pressure and total temperature of the blowing jet. Several kinds of gases and mixtures as blowing jet were discussed and analyzed.2, Experiments were carried out to investigate the SWBLI phenomenon in a two-dimensional hypersonic inlet with two wedge ramps, especially for the condition when the inlet is close to unstarting flow. Roughness surface and vortex generators were used to impair the separation at the corner of two ramps. Separations arising at downstream of the cowl at different conditions of free stream were analyzed and discussed. Effect of bleeding to weaken the viscous separation was also evaluated by numerical simulation.3, A new kind of tuft method, which is conventionally used in low speed wind tunnels, was developed for using in the shock tunnel to observe details of flow field close to the surface. It was proved that the tuft method can visualize the near-wall dynamic behaviors effectively. SWBLI phenomenons over three-dimensional configurations were investigated by the tuft method, oil dot visualization and numerical simulation. Flow structures and some related parameter variations on the surface were revealed and analyzed.4, Several kinds of flow visualization technology were employed to observe flow field in the three-dimensional hypersonic inlet, which were also analyzed with supplement from the results of simulation. Bleeding was also examined to evaluate the control effectiveness of the separation.5, Some experimental results of shock wave/shock wave interaction were demonstrated, which is helpful for the better understanding of this flow phenomena.