A Parametric Experimental Study for Momentum Transfer by Plasma Actuator

Momentum transfer performance of the plasma actuator was investigated experimentally for a variety of parameters including an ambient gas pressure, ambient gas species, alternating high voltage wave form, electrode configuration and dielectric plate material. It was found that an ambient gas pressure, under which a plasma actuator operates, has a significant effect on the momentum transfer performance. In fact, the performance does not decrease in a liner manner with decreasing an ambient gas pressure, but increases at first and then decreases. This suggests that the discharge manner, which governs the momentum transfer performance, significantly depends on the ambient gas pressure. Chemical species of an ambient gas has also a significant effect on the momentum transfer performance; The momentum transfer in air is larger than that in nitrogen gas over an entire pressure range less than 1 atm. This suggests a significant contribution of oxygen molecule in air. The momentum transfer performance in carbon dioxide gas is slightly larger than that in nitrogen gas over an entire pressure range less than 1 atm while they are comparable at a pressure of 1 atm. It was also found that the wave form of the high voltage has a significant effect; 1) the steeper the up-going part of the high voltage wave is, the larger the momentum transfer is, 2) both negative and positive part of the sinusoidal wave equivalently are foundamental for the net momentum trasfer and have a significant contribution to the momentum transfer. Furthermore the configuration of electrode were found to be an effective factor for the momentum transfer performance in a plasma actuator. Especially, a mesh type electrode can improve the performance significantly. Finally we clarified the effect of the material of the dielectric plate on the momentum transfer performance; The momentum transfer depends on the dielectric plate material in a manner depending on the ambient gas pressure.