The interaction of plasma gas with the surrounding atmosphere in plasma arc cutting (PAC) has been investigated using high-speed Schlieren imaging. The time-series corresponding to the recorded intensity of each pixel have been post-processed using statistical analysis. Two different methods that highlight the time variation of the amplitude of the fluctuations in the density field have been compared: the windowed standard deviation and the GARCH approach. Whereas a mean-variance analysis can provide at most time-averaged results, GARCH can model the instantaneous variation of the luminous signal, thus providing new insights on the time evolution of the turbulence around the arc.
V. Colombo, A. Concetti, E. Ghedini, P. Sanibondi, G. Cantoro, F. Zinzani (2011). Statistical Analysis of High-Speed Schlieren Imaging in PAC. IEEE TRANSACTIONS ON PLASMA SCIENCE, 39(11), 2898-2899 [10.1109/TPS.2011.2148128].
Statistical Analysis of High-Speed Schlieren Imaging in PAC
COLOMBO, VITTORIO;CONCETTI, ALESSIA;GHEDINI, EMANUELE;SANIBONDI, PAOLO;CANTORO, GIANMATTEO;
2011
Abstract
The interaction of plasma gas with the surrounding atmosphere in plasma arc cutting (PAC) has been investigated using high-speed Schlieren imaging. The time-series corresponding to the recorded intensity of each pixel have been post-processed using statistical analysis. Two different methods that highlight the time variation of the amplitude of the fluctuations in the density field have been compared: the windowed standard deviation and the GARCH approach. Whereas a mean-variance analysis can provide at most time-averaged results, GARCH can model the instantaneous variation of the luminous signal, thus providing new insights on the time evolution of the turbulence around the arc.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
