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Journal of Flow Visualization and Image Processing

ISSN Print: 1065-3090
ISSN Online: 1940-4336

Journal of Flow Visualization and Image Processing

DOI: 10.1615/JFlowVisImageProc.2016016980
pages 15-24

VISUALIZATION OF FLOW BY BLAST WAVES PRODUCED BY PULSED DISCHARGE

Irina A. Znamenskaya
Faculty of Physics, Lomonosov Moscow State University, 1−2 Leninskiye Gory, Moscow, 119991, Russia
Professor of Moscow Aviation University
Igor Doroshchenko
Faculty of Physics, Lomonosov Moscow State University, 1−2 Leninskiye Gory, Moscow, 119991, Russia
Dmitry S. Naumov
Faculty of Physics, Lomonosov Moscow State University, 1−2 Leninskiye Gory, Moscow, 119991, Russia
Igor Ivanov
Faculty of Physics, Lomonosov Moscow State University, 1−2 Leninskiye Gory, Moscow, 119991, Russia
Tahir A. Kuli-Zade
Faculty of Physics, Lomonosov Moscow State University, 1−2 Leninskiye Gory, Moscow, 119991, Russia

ABSTRACT

An experimental investigation of combined discharge (pulse volume discharge with preionization by plasma electrodes) was carried out: glow time and space characteristics, analysis of flow with discharge-produced blast waves. The contracted volume discharge (spatial gas discharge mode in contracted form) was considered as electrical breakdown − a 24-mm-long vertical plasma column was formed. As a result of the nanosecond-lasting breakdown, the internal energy of the gas increased and the pressure raised up, which led to the formation of gas flow with cylindrical shock (blast) waves. The flow evolution was visualized with the aid of high-speed shadowgraphy. The blast waves were recorded, their position and speed were measured; the instability of the post-discharge hot gas channel was also visualized. A two-dimensional numerical simulation of flow based on the Euler equations was performed. The model of pulse cylindrical energy deposition was used; initial conditions were taken from experimental data. An inverse problem was solved by comparing CFD with the position of experimental shock waves. It was shown that 20−22% of the combined discharge energy, stored in the capacitor, was converted into the internal gas energy (about 140-155 mJ). Shock waves from surface discharges were also visualized and analyzed.