Quantitative study of the control of hypersonic aerodynamics using millisecond pulsed discharges

Abstract

The experimental study of the high-speed aerodynamic control using pulsed discharges is a fundamental yet relatively unexplored issue. This is because the strong electromagnetic interference (EMI) caused by these discharges can affect the accuracy of conventional measurements. A quantitative knowledge of this issue can help to evaluate the aerodynamic control capabilities of pulsed discharges. Therefore, in this study, a fiber-optic balance based on a Fabry-Pérot sensor, which is not subject to EMI, was applied to the acquisition of aerodynamic data with pulsed discharges in a Mach-6 flow. The pulsed discharges were characterized by a long pulse width of around 1 ms and a low frequency of 100 Hz. There was notable variation in the axial force under these pulsed discharges, which indicates their effectiveness for shock manipulation. In the presence of a pulsed discharge, fast-response Schlieren imaging revealed both shock-attenuation and thermal-choking effects in the aerodynamic control. The balance data indicate that the rate of axial-force reduction increases linearly with discharge pulse energy, but it decreases parabolically with increasing angle of attack.