Experimental and Numerical Characterization of a Plasma-Driven Jet Actuator for Active Control of Turbulent Base Flow Phenomena

Abstract

Subject is the characterization of a plasma-driven jet actuator for active control of turbulent base flow phenomena. The motivation is to determine its suitability with respect to generic launcher geometries focused on the transonic part of a typical ascend trajectory. A configuration, based on the known SparkJet concept, is implemented and investigated by means of experimental and numerical characterization. High-speed Schlieren visualization and the results of transient axisymmetric CFD simulations are being compared in terms of topological features and quantitative distance–time and velocity–time information on the jet propagation to find out its range of operating conditions. Crossflow velocities in the range of 500 to 1000m/s utilizing high-energy jets of up to 16J of capacitive energy could be achieved. For lower energy setups, maximum actuation frequencies are found to be greater than 20kHz in a natural resonant circuit, which is assumed to be sufficient for periodical excitation of base flow instablities. The examined concept of plasma-ctuation is considered highly flexible with respect to different actuation mechanisms. Therefore, further investigations are proposed to focus on low-energy impulses directly influencing stability modes following the modern understanding of active flow control.