Plasma Synthetic Jet Actuators for Active Flow Control

Abstract

The plasma synthetic jet actuator (PSJA), also named as sparkjet actuator, is a special type of zero-net mass flux actuator, driven thermodynamically by pulsed arc/spark discharge. Compared to widely investigated mechanical synthetic jet actuators driven by vibrating diaphragms or oscillating pistons, PSJAs exhibit the unique capability of producing high-velocity (>300 m/s) pulsed jets at high frequency (>5 kHz), thus tailored for high-Reynolds-number high-speed flow control in aerospace engineering. This paper reviews the development of PSJA in the last 15 years, covering the major achievements in the actuator working physics (i.e., characterization in quiescent air) as well as flow control applications (i.e., interaction with external crossflow). Based on the extensive non-dimensional laws obtained in characterization studies, it becomes feasible to design an actuator under several performance constraints, based on first-principles. The peak jet velocity produced by this type of actuator scales approximately with the cubic root of the non-dimensional energy deposition, and the scaling factor is determined by the electro-mechanical efficiency of the actuator (O(0.1%–1%)). To boost the electro-mechanical efficiency, the energy losses in the gas heating phase and thermodynamic cycle process should be minimized by careful design of the discharge circuitry as well as the actuator geometry. Moreover, the limit working frequency of the actuator is set by the Helmholtz natural resonance frequency of the actuator cavity, which can be tuned by the cavity volume, exit orifice area and exit nozzle length. In contrast to the fruitful characterization studies, the application studies of PSJAs have progressed relatively slower, not only due to the inherent difficulties of performing advanced numerical simulations/measurements in high-Reynolds-number high-speed flow, but also related to the complexity of designing a reliable discharge circuit that can feed multiple actuators at high repetition rate. Notwithstanding these limitations, results from existing investigations are already sufficient to demonstrate the authority of plasma synthetic jets in shock wave boundary layer interaction control, jet noise mitigation and airfoil trailing-edge flow separation.

Dynamic Stall Control around Practical Airfoil Using Nanosecond-Pulse-Driven Dielectric Barrier Discharge Plasma Actuators

“…Especially in unsteady flow, the flow field changes from moment to moment, and therefore, a model to estimate the development of the flow field [5] and an active flow control device to produce the best control effect in each flow field are required. Some existing types of active flow control devices include the plasma synthetic jet actuator [6,7] and the dielectric barrier discharge plasma actuator (DBDPA). A DBDPA generates plasma by applying a voltage to a dielectric between two electrodes, and therefore, it is highly responsive and has a simple structure.…”

Active Control of Bluff-Body Flows Using Plasma Actuators

“…The practical disadvantages of PSJAs are due to the high gas temperatures that can be reached within the cavity and the interference of electromagnetic fields [60]. A review of several practical issues related to PSJA design and integration, its characterization in quiescent flow, low-order analytical models, and numerical simulations of the induced synthetic jets as well as of some recent examples in AFC applications can be found in the work by the authors of [61].…”

A novel de-icing strategy combining electric-heating with plasma synthetic jet actuator

“…25 It has the merits of both the plasma actuator and the zero net flux jet. 26 Generated by the instantaneous energy deposition from a high voltage pulsed arc discharge, 27 the pressure within the actuator chamber can reach a value of hundreds of kilopascals. 28 Since PSJA has abundant advantages such as no need for moving parts and external air sources, 25 high jet velocity, [29][30][31] wide-bandwidth, 32 and extremely fast response, 33,34 its application prospects in the flow control field are becoming more and more promising.…”