Influence of low ambient pressure on the performance of a high-energy array surface arc plasma actuator

In order to solve the problem of single arc plasma actuator's failure to suppress the boundary layer separation, the effectiveness of the array surface arc plasma actuator to enhance the excitation intensity is verified by experiment. In this study, an electrical parameter measurement system and high-speed schlieren technology were adopted to delve into the electrical, flow field, and excitation characteristics of the high-energy array surface arc plasma actuator under low ambient pressure. The high-energy array surface arc discharge released considerable heat rapidly;as a result, two characteristic structures were generated, i.e., the precursor shock wave and thermal deposition area. The duration increased with the increase in environmental pressure. The lower the pressure, the wider the thermal deposition area's influence range. The precursor shock wave exhibited a higher propagation speed at the initial phase of discharge;it tended to decay over time and finally remained at 340 m/s. The lower the environmental pressure, the higher the speed would be at the initial phase. High-energy array surface arc plasma actuator can be employed to achieve effective high-speed aircraft flow control.

Research Progress of hypersonic boundary layer transition control experiments

Hypersonic boundary layer transition is a hot yet challenging problem restricting the development and breakthrough of hypersonic aerodynamics.In recent years,despite great progress made by wind tunnel experiment,transition mechanism and transition prediction,only partial knowledge has been gained so far.In this paper,firstly,the specific scenarios of hypersonic boundary layer transition control are clarified.Secondly,the experimental research progress and mechanism of passive control and active control methods under different hypersonic transition control demands are summarized,with their advantages and disadvantages being analyzed separately.Plasma actuation is easy to produce controllable broadband aerodynamic actuation,which has potential in the field of boundary layer transition control.Hence,the following part of the paper focuses on plasma flow control.The feasibility of plasma actuation to control the hypersonic boundary layer transition is demonstrated and the research ideas are presented.Finally,hypersonic boundary layer transition control methods are summarized and the direction of future research is prospected.