Numerical Simulation of Pin-Plane Discharge for Plasma-Assisted Combustion of Hydrogen

At or near atmospheric pressures, most electrical discharges develop as an ionization front known as streamers. In early phases of streamer, the plasma formed is non-thermal. However, the streamers develop into filamentary arc-like plasma if not terminated by limiting the pulse width. We report on the numerical results of screamer development and propagation in pin-plane electrode geometry. The effect of pin diameter on the formation of reactive species in hydrogen/air plasma, which is important for plasma-assisted combustion, is discussed. The Laplacian field has significant enhancement at the electrode tip as the pin radius is decreased. The results show that the initial development is dependent on the tip radius but once away from the tip, the pin radius has very little impact on streamer propagation as the electrode gap is increased.