Research On Characteristics Of Shock Wave/Boundary Layer Interactions In Bump Inlet

There are complex three-dimensional shock/boundary layer interactions in bump inlet,which behave different to conical shock/boundary layer interactions,and may have signicant influences on the flow quality captured by the inlet and the aerodynamic performance of the inlet.In order to investigate the flow field characteristics of conical shock wave/boundary layer interactions induced by bump,numerical and experimental researches were carried out.Furthermore,the characteristics of the terminal normal shock wave/boundary layer interactions were also numerically studied.Firstly,the flow filed of a single-cone bump designed by streamline tracing technology was analyzed,the results indicate that the flow behaves in a quasi-conical similarity manner.Compared to the semi-cone and semi-rhombic cone,the bump shows the excellent ability of diverting the boundary layer and has low flow distortion on the exit plane.This is one of the important reasons why it is selected as the compression ramp for bump inlet.Besides,increasing the design Mach number appropriately can improve the bump's ability of diverting the boundary layer.However,if the design Mach number is too high,the ability of diverting the boundary layer almost keeps invariant,but the total pressure loss increases rapidly.Then,the flow field characteristics of bumps with different shock wave system arrangements were analysed.The results show that increasing the wave number can weaken the conical shock strength,which leads to a low total pressure loss in the core and separation flow region.Meanwhile,this arrangement can also lower the exit flow distortion with a high level of diverting the boundary layer.And the total pressure recovery coefficient will go higher with the increasing of the wave number,which is more obvious at high Mach number.In addition,wind tunnel tests were conducted,which validate the numerical methods and confirm the above conclusions.At last,the terminal normal shock/ boundary layer interactions in bump inlet were numerically studied.It is found that the normal shock shows strong three dimensional characteristics under the supercritical state due to the interference of the side wall swept shocks.Under the subcritical state,as the normal shock transports upstream,the inlet's ability of diverting the boundary layer enhances.As a result,the total pressure recovery coefficient of the bump inlet can be kept at a high level while the inlet can still operate stably.