Research On Control Method Of Bump Surface Induced Flow Field Based On Plasma Synthetic Jet

When the Bump inlet works normally,the shock wave/ boundary layer interactions induced by the compression surface of the bump will greatly reduce the inlet flow field quality.In order to alleviate the adverse effects of bump-induced surface shock / boundary layer interference and thereby improve the performance of Bump inlets,this paper uses simulation methods to reveal the plasma for two different types of actuator arrangements based on momentum effects and vortex effects.The control effect of the synthetic jet on the bump-induced flow field was explored,and the appropriate actuator layout parameters were explored.Firstly,the simulation method of the bump model was explored,a two-dimensional simulation and a three-dimensional simplified simulation of the plasma synthetic jet exciter model were performed using phenomenological simulation method.The three-dimensional simulation method of plasma synthetic jet solves the problem of large calculation time and long calculation time in the previous method,and can accurately capture the velocity characteristics of the jet's precursor shock wave and jet mass.Secondly,the single-cone bump-induced flow field in the design state and side-slip condition was studied,and the effect of different sideslip angles on the bulge-induced flow field was analyzed.The results show that: under the design state,the surface shock induced by the front edge of the bump and the boundary layer of the incoming flow form a "?" wave system structure.There is a large separation zone under the wave foot,and the flow topology of the separation zone is quasi-conical.The sideslip of the incoming air flow increases the pressure gradient of the windward side of the bump and shifts the high-pressure center of the bump surface to the windward side,resulting in increased vortex strength at the front edge of the windward and loss of total pressure recovery at the windward side.With the increase of sideslip angle,the quasi-conical similarity characteristics of the windward separation area increased,the virtual cone angle increased from 19.8 ° to 37.5 °,and the leeward surface gradually developed from quasi-conical similarity to quasi-cylindrical similarity.Subsequently,the effect of the plasma synthesis jet based on the momentum effect on the bumpinduced flow field control was simulated,and the effectiveness of the control method was verified.The influence of parameters such as the position of the actuator and the slit width on the jet control effect was obtained.For an actuator with a slit width of 2mm,the effective time of the plasma synthetic jet is a quarter of a cycle.During this time,it can suppress the bump surface induced shock,and promote the bump to remove the boundary layer.At the same time,it will bring the separation point ahead,weaken the separation strength,make the bump surface boundary layer fuller,and reduce the wall resistance.In the range of parameters explored in this article,the instantaneous jet flow can reduce the resistance of the bump wall by up to 3.2%.Finally,the effect of the plasma-synthesized jet based on the vortex development on the druminduced flow field was simulated,and the effectiveness of the control method was verified.The influence of parameters such as the position,angle and width of the actuator on its control effect is revealed.The results show that after the jet group moves to the separation zone in the benchmark control scheme,the degree of streamline backflow in the separation zone will decrease.At the same time,the development of the vortex promotes the mixing of the fluid and the mainstream in the downstream boundary layer of the bump,and enhances the ability of the boundary layer to resist the reverse pressure gradient.The jet instantaneously reduces the maximum length of the separation area on the surface of the bump by 17%,at the same time reduces the shape factor of the boundary layer and makes the downstream velocity profile of the exciter fuller.