PLASMA ACTUATORS FOR BOUNDARY LAYER CONTROL OF NEXT GENERATION NOZZLES

DBD plasma actuators are simple devices comprising two electrodes separated by a dielectric layer. One of the electrodes is covered by the dielectric layer and is completely insulated from the other one, which is exposed to the atmosphere in the top of the dielectric layer. The DBD plasma actuator operates by applying to the two electrodes an high voltage at high frequency from a power supply. When the amplitude of the applied voltage is large enough, in the exposed electrode, an ionization of the air (plasma) occurs over the dielectric surface which, in the presence of the electric field gradient, produces a body force on the ionized air particles. This induces a flow that draws ionized air along the surface of the actuator and it accelerates this neutral air towards downstream, in a direction tangential to the dielectric. Herein we will present this next generation plasma actuator for boundary layer control, which is demonstrated on the acceleration of the flow in a Coanda nozzle wall, thus contributing to help vectoring the exit jet flow. It will be shown that using only the plasma actuator it will be possible to vectorize the exit jet flow even under pure axial flow at the nozzle exit. Experimental results are obtained using flow visualization and Particle Image Velocimetry.