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.