Method to quantify the electrical efficiency of a ns-DBD plasma actuator

Abstract

An experimental investigation was conducted on the effective efficiency of a nanosecond Dielectric Barrier Discharge (ns-DBD) plasma actuator. Back-current shunt technique and infrared thermography measurements were carried out at the same time on an upside-down flat plate in a quiescent environment. The only investigated parameter was thickness of the dielectric barrier. Voltage amplitude and frequency of discharge were kept constant at maximum values allowable by the used power generator, i.e. 10k Volt and 10k Hz respectively. The selected material for the dielectric barrier was Makrolon(r) because of its well know thermal and dielectric propriety. Energy input was calculated as difference between the pulse voltage given and the one reflected back into the system via back current shunt technique. Ideal power flux obtained if all the input energy was converted to heat is then calculated. The actual power flux was obtained by solving an IHTP (Inverse Heat Transfer Problem) once the transient temperature distribution on the surface of the dielectric barrier was measured by means of IR thermography. The ratio between these two values represents a quantification of electrical efficiency of an ns-DBD plasma actuator. Results prove the high performances of ns-DBD plasma actuator in the respect of energy deposition and that the efficiency depends on the thickness of the barrier.