Numerical Analysis of Initialization of a Nanosecond-Pulsed Dielectric Barrier Discharge Actuator

In this work a nanosecond-pulsed dielectric barrier discharge actuator is simulated to investigate the plasma and surface charge behavior during the startup phases of a given pulse sequence. A potential of plus/minus 1.2 kV is applied sinusoidally with a total pulse width of 100 ns over five full pulses. These results show that plasma development changes substantially between the first three pulses, where the distribution of free electrons resulting from the previous pulse influences the development of the plasma sheath and hence the downstream extent of the bulk plasma. Between the third and fifth pulses, a negative surface charge region persists at the downstream extent of the plasma, which generates an electron void, thus inhibiting the development of a strongly ionizing plasma sheath. These results show that by five pulses the plasma has reached its maximum extent and that for the purposes of establishing average values the first two pulses should not be considered representative of the longer-term plasma behavior.