Resonant Excitation of Boundary Layer Instability of DC Arc Plasma Jet by Current Modulation

0367145 - ÚFP 2012 RIV DE eng J - Journal Article
Kopecký, Vladimír - Hrabovský, Milan
Resonant Excitation of Boundary Layer Instability of DC Arc Plasma Jet by Current Modulation.
Plasma Chemistry and Plasma Processing. Roč. 31, č. 6 (2011), s. 827-838. ISSN 0272-4324. E-ISSN 1572-8986
R&D Projects: GA ČR GAP205/11/2070
Institutional research plan: CEZ:AV0Z20430508
Keywords : dc arc jet * plasma jet oscillations * boundary layer instability * frequency spectra
Subject RIV: BL - Plasma and Gas Discharge Physics
Impact factor: 1.602, year: 2011
http://www.springerlink.com/content/v160841757161758/

Instabilities of thermal plasma jets were studied on the basis of analysis of plasma radiation fluctuations recorded by an array of high frequency photodiodes. Characteristic frequencies of jet oscillations were found and spatial distribution of amplitude of plasma fluctuations was determined. The influence of arc current ripple on plasma instabilities was investigated for two types of power supply - classical thyristor controlled unit with the frequency of the current ripple 300 Hz and the rectifier with the high frequency converter and frequency of the current modulation 30 kHz. Generation of boundary layer instability with the current modulation frequency and its harmonics was proved using fast Fourier transform, contour plots and phase portraits. It was found that the character of fluctuations of plasma jet was substantially influenced by current ripple with the frequency or its harmonics close to the frequency of oscillations generated by boundary layer instability.
Permanent Link: http://hdl.handle.net/11104/0201915