ISSN 2079-3537      

 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                             

Scientific Visualization, 2019, volume 11, number 3, pages 76 - 87, DOI: 10.26583/sv.11.3.07

Visualization of the interaction region of an oblique shock wave with a boundary layer by the radiation of a nanosecond surface sliding discharge

Authors: I. Mursenkova1, A. Sazonov2, Yu. Liao3, I. Ivanov4

Lomonosov Moscow State University

1 ORCID: 0000-0002-7181-4533, murs_i@physics.msu.ru

2 ORCID: 0000-0002-7930-9283

3 ORCID: 0000-0002-5776-1949

4 ORCID: 0000-0002-7786-6780

 

Abstract

The spatial structure of radiation of a surface sliding discharge with a duration of ~ 300 ns (plasma sheet) in inhomogeneous supersonic air flows including oblique shock wave in a discharge chamber of shock tube was experimentally investigated. The flows were created behind plane shock waves with Mach numbers 2.84.2; flow Mach numbers were 1.30-1.60. The flow in the discharge chamber included an oblique shock wave generated by the interaction of a supersonic flow with a small obstacle, and then reflected from the upper wall of the discharge chamber. In this case, the shock wave interacted with the boundary layer of the supersonic flow, which formed on the streamlined wall. A surface sliding discharge with a length of 100 mm and 30 mm wide was initiated on a streamlined surface at a certain moment in time. The discharge current, emission spectra, and spatial characteristics of the radiation under various conditions of discharge initiation were obtained and analyzed in experiments. The time dependence of geometry of the discharge glow region was obtained by digital processing of discharge images in flows. CFD simulation was performed to determine the shock-wave structure of the flow in the channel with an obstacle under experimental conditions. The comparison of experimental data with the results of numerical calculation of the supersonic flow field was done. It was shown that the spatial distribution of radiation from a surface sliding discharge visualizes the low density areas and the separation zone formed under the interaction of an oblique shock wave with a boundary layer.

 

Keywords: Flow vizualization by the discharge radiation, nanosecond surface sliding discharge, oblique shock wave, boundary layer, flow separation zone, cfd simulation.