Gasdynamic Instabilities during Decay of the Submicrosecond Spark Discharge Channel

This work is devoted to studying the dynamics of breakdowns of submicrosecond high-voltage electric discharge and discharge-accompanying hydrodynamic phenomena and to analyzing the possibility of its application for acceleration of the component mixing in solving high-speed combustion problem. This work presents the results of experimental and numerical studies of the development of gasdynamic disturbances during the afterspark channel decay. The main parameters of the discharge are as follows: the typical length is $50$–$60$ mm, the breakdown voltage is up to $120$ kV, the duration time is $80$–$100$ ns, the energy is up to $2$ J, and the order of magnitude of the instantaneous power is $100$ MW. For the first time, jet-type instabilities have been studied in detail and described. It is shown that the development of large-scale instabilities is tightly related to the discharge channel geometry. The mechanism of the breakdown development and the related possibility of controlling the discharge channel shape are discussed.