Numerical simulation of hypersonic plasma flow field disturbed by pulsed discharge

A plasma sheath will be generated around the hypersonic vehicle during reentry, and a large number of electrons in the plasma sheath will seriously affect the communication between the vehicle and the ground station. In order to reduce the electron number density of the hypersonic vehicle plasma sheath, a method of using pulsed discharge active actuation to regulate the plasma sheath is proposed. Based on the air dissociation and ionization model including 11 components and 32 chemical reactions, the reduction effect of pulsed discharge actuation on the electron density of plasma sheath is studied by numerical simulation. A first test is performed in which the pulsed discharge is compared with the plasma jets' experimental data. Then, a second test compared the plasma flow field around the RAMC-II vehicle with the flight test and NASA data. In these two tests, the simulation results are basically consistent with the experimental results. Finally, the effect of pulsed discharge with different energy density on the plasma sheath electron density is studied. The numerical results show that the interaction between the high-pressure aerodynamic actuation generated by the actuator and the plasma sheath produces an obvious shock wave, which blocks electrons from flowing downstream, reduces the velocity and pressure of the flow field behind the shock wave, and, finally, makes the electron density downstream of the actuator attenuate significantly, with the maximum attenuation amplitude of about 35%. Compared with the traditional method, the method proposed in this paper requires less space, load, and source power and has certain engineering feasibility.