BLAST WAVE-PROPAGATION IN GLOW TO SPARK TRANSITION IN AIR

The formation and propagation of post-discharge blast waves are studied theoretically and the minimum rate of energy transfer between electrons and neutral particles is deduced in the case of a positive point-to-plane discharge in air, described and numerically analyzed in a previous paper by the authors. In this type of discharge, the injection of energy in the discharge is spread in time. The blast waves generated by the discharge constitute a set of waves with a complex structure. The classical analysis of blast waves was adapted to our experimental situation in which the energy injection is spread in time and space. The influence of the injected energy of the expansion radius of the wave has been studied and we show that the minimum rate of energy transfer f//m//i//n between electrons and neutral particles in the glow to spark transition can be deduced from the Schlieren records. In the experiments analyzed, the rate of energy transfer f is greater than 20 plus or minus 6%.