The characteristics of a distributed sliding surface discharge with a duration of ~300 ns (plasma sheet) in a non-uniform supersonic airflow with a vortex zone behind a thin wedge have been studied in a shock tube channel. The spatial distribution of the discharge radiation, the spectra of the discharge radiation, and the discharge current are analyzed in the flows behind plane shock waves with Mach numbers 2.4-3.5 (Mach numbers of flows 1.16-1.47, density 0.02-0.20 kg /m3. It is shown that in an airflow with a vortex zone, the surface discharge develops as a channel 1-3 mm wide, located in the region of low density behind the wedge. The calculated electron concentration in the discharge channel is an order of magnitude higher than the electron concentration when a discharge is initiated in a homogeneous medium.
47.40.Ki Supersonic and hypersonic flows
47.11.-j Computational methods in fluid dynamics
$^1$MSU, Faculty of Physics