Development and Application of Energetic Actuators for Shear and Vortex Dominated Flow Control.

摘要

Active supersonic flow control has been a significant challenge due to the high momentum requirements to produce effective control. It was to this end that Johns Hopkins University developed the SparkJet Actuator (SJA) in collaboration with Florida State University under AFSOR sponsorship. This unsteady, dynamic actuator was tested on the benchtop over various quiescent conditions. The promising results led to a benchmark achievement of supersonic wind tunnel testing over several operating conditions. The SparkJet actuator is a zero net mass flux (ZNMF) device that generates synthetic jets through the use of an electrical discharge. Electrodes inside of a cavity connected to a capacitor bank are discharged at fixed frequencies. The high temperature from the electrical discharge increases the pressure inside of the cavity, and an orifice array located on the cavity allows the air to escape thus creating the jets used for flow control. A 1-D numerical model was developed at the Johns Hopkins University to predict the output of the actuator in terms of cavity volume, energy deposition, number of orifices and orifice diameters.