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To suppress the high frequency combustion instability of rocket engines, quasi-direct current (quasi-DC) discharge plasma is considered in combination with special arrangements in a rocket engine combustor. After establishing an internal reacting flow field model of a rocket combustor and a phenomenological plasma model, the influence of quasi-DC discharge plasma on high frequency combustion instability is numerically investigated. The results show that the characteristics of the high frequency combustion instability in the combustor are captured very well through the simulation. Based on the DES turbulence model, a positive feedback process is clearly observed for the self-excited combustion instability. The mean temperature and pressure of the combustor are not sensitive to the occurrence of quasi-DC discharge plasma. The pressure histories of the combustor and their characteristic oscillating frequencies are not affected by the plasma when only one actuator is in operation. However, the oscillating amplitudes of the pressure are reduced within a certain time when several actuators are in operation. The heat release becomes more diffusive and more eddies form around the injector faceplate with an increasing number of plasma filaments. Mainly through the reduction of local heat release, the plasma is capable of affecting the high frequency combustion instability in the combustor. To better control high frequency combustion instability, the optimal arrangement is a double-plasma filaments with symmetrical actuators.

The evolutions of dielectric barrier discharge (DBD) plasma induced starting vortex and the transformation of the DBD plasma induced flow field at different operating pressures are obtained by particle image velocimetry. The results show that the starting vortex will diffuse to the embedded electrode side and then disappear, and the diffusivity will decrease as the time goes on at high operating pressure. But the starting vortex will not change in location, and it will not disappear at low operating pressure. As the operating pressure decreases, the starting time of plasma induced flow field decreases, the ordinate orientation of the induced flowfield increases, and the landscape orientation of the induced flowfield decreases. The form of the induced streamline will come through L→U→V as the pressure decreases. There is no induced vortex in the form of L. There are two induced vortexes in the form of U which lay in the middle and on the right hand of the form U respectively, and there is one induced vortex in the form of V which lays in the middle of form V.

The experiments to generate vortices continuously using sub-microsecond pulsed surface dielectric barrier discharge (SDBD) actuator are conducted by particle image velocimetry (PIV). The double-frequencies actuation mode is presented which includes repetitive pulse frequency and vortex frequency. It is found that the empty zone of PIV particles appears in the place where the particles are quite few even nil during the experiments. When discharges occur the primary empty zone is produced by the micro explosion due to the released heat of plasma, and when discharges end the secondary empty zone appears. The induced flow is farther apart form wall and the influence of wall friction should be suppressed due to primary empty zone. When the secondary empty zone on the left side of actuator exposed electrode is blown away completely, the next actuation can start. In order to control the flow more effectively, the pulse voltage with higher repetitive frequency should be applied. The pulse number during one vortex time should be more than 10. As the pulse number increases, the maximal velocity of induced flow increases but the momentum transfer efficiency decreases. The mechanisms releasing heat and body force can be triggered by using the sub-microsecond pulse SDBD actuator.

Based on the physical processes of dielectric barrier discharge (DBD) and quasi-direct-current (quasi-DC) discharge, the plasma aerodynamic actuation mechanism is analyzed, then the numerical model of plasma aerodynamic actuation is founded, finally the DBD and the quasi-DC discharge plasma flow control processes are simulated in the cases of low velocity and high velocity. The results show that the aerodynamic actuation mechanism of DBD plasma is that the discharge changes three kinds of forces in continuum fluent medium, these being shear stress caused by Newton friction, body force caused by electro hydrodynamic and impulsive active force caused by pressure change, and the main aerodynamic actuation mechanism of DBD plasma is body force caused by electro hydrodynamic. The effect of body force is stronger in near space than in the sea level, plasma induced flow velocity increases in near space. The main aerodynamic actuation mechanism of quasi-DC discharge plasma in supersonic air flow is the thermal mechanism of heat plasma, the exploding wires diathermanous model found in this paper is good for the simulation of the process of surface quasi-DC discharge plasma incident shock. The effect of quasi-DC discharge plasma on the supersonic flow field is conform with the effect of protuberance with a bevel to the supersonic flow field, so it can be used to control the shock wave in supersonic aircraft.