Boundary layer bleeding of three-dimensional compression hypersonic inlet

Various methods of boundary layer bleeding were investigated to control the streamwise vortices generated by shock/boundary layer interaction in the isolator of three-dimensional compression hypersonic scramjet inlet.The boundary layer flow patterns were visualized by oil dot technique and numerical simulation.And the effect of different bleedings on inlet performance was then analyzed.It was revealed that the streamwise vortices were mainly attributed to the boundary layer separation on the sidewall,and the bleeding on the sidewall separation is effective.Compared to the bleeding around the attachment line,the bleeding on the separation zone remarkably reduced the boundary layer separation and effectively diminished the development of the vortex structure,which ultimately contributed to higher total pressure recovery at the inlet exit.Moreover,the flow uniformity was improved as the bleeding area increasing,while at the cost of more mass loss.