Numerical Investigation on Flow Control of a Hypersonic Airfoil by Plasma Synthetic Jet

Abstract

Plasma synthetic jets (PSJs) have received widespread attention because of their rapid response capability. The use of PSJ shock and thermal effects for active flow control has been investigated in many recent studies. Through numerical simulation, this study found that the geometric position of a PSJ actuator on an airfoil surface is the key factor affecting flow control effects. Different geometric positions have different effects on the lift-drag characteristics of an airfoil, and the flow control mechanism has different components. The flow control mechanism can be divided into three types: the thermal effect, the coupling of the thermal effect and single shock, and the coupling of thermal effect and multiple-shock rebound. The concept of distance lplacement provides a reference for determining the geometric arrangement of a PSJ actuator. This study showed that in addition to improving the lift-drag characteristics of an airfoil by reducing drag, directly increasing lift is also a new choice. In addition, in a confirmatory experiment, the nanosecond pulse PSJ actuator pushed the bow shock in a Mach 5 flow; the longest distance was about 1% of the characteristic length of the airfoil.