Effect of gas flow on post-arc gap recovery

Spark reignition voltage characteristics have been measured for gaps between stationary electrodes for various controlled speeds of gas flow following d.C. pulsed arc discharges. By varying the gap geometry, electrode material and duration of the initial arc, the influence of both the gas flow and the electrodes on the detailed shapes of the characteristics have been determined and qualitatively explained. A crude theoretical approach is described, in which the variation of spark reignition voltage is satisfactorily accounted for in terms of the average gap density as controlled by the initial electrode heating, the time constants of the conductive cooling of the gas and the electrodes, and the heat transport by the gas flow through the gap.