The fluid-dynamic characterization by means of Schlieren high-speed imaging of the effluent region of a single electrode plasma jet is presented. The plasma source is powered by a high-voltage generator producing pulses with nanosecond rise time. Time evolution of fluctuations generated in a free flow regime and when the jet is impinging on substrates of different geometries (plain substrates, Petri dishes, etc.) and materials (metal, dielectric covered metal, polystyrene) has been investigated. Plasma ignition causes fluiddynamic instabilities moving in the direction of the jet flow and correlated with the highvoltage pulses: for low pulse repetition frequency (PRF) (\125 Hz), the movement of the turbulent front between two voltage pulses can be tracked, whereas for higher PRF (1,000 Hz) the flow is completely characterized by turbulent eddies in the effluent region, without relevant changes between subsequent voltage pulses. When the jet is impinging on a substrate, turbulent fronts propagate over the surface starting from the gas impinging zone.
M. Boselli, V. Colombo, E. Ghedini, M. Gherardi, R. Laurita, A. Liguori, et al. (2014). Schlieren High-Speed Imaging of a Nanosecond Pulsed Atmospheric Pressure Non-equilibrium Plasma Jet. PLASMA CHEMISTRY AND PLASMA PROCESSING, 34, 853-869 [10.1007/s11090-014-9537-1].
Schlieren High-Speed Imaging of a Nanosecond Pulsed Atmospheric Pressure Non-equilibrium Plasma Jet
BOSELLI, MARCO;COLOMBO, VITTORIO;GHEDINI, EMANUELE;GHERARDI, MATTEO;LAURITA, ROMOLO;LIGUORI, ANNA;SANIBONDI, PAOLO;STANCAMPIANO, AUGUSTO
2014
Abstract
The fluid-dynamic characterization by means of Schlieren high-speed imaging of the effluent region of a single electrode plasma jet is presented. The plasma source is powered by a high-voltage generator producing pulses with nanosecond rise time. Time evolution of fluctuations generated in a free flow regime and when the jet is impinging on substrates of different geometries (plain substrates, Petri dishes, etc.) and materials (metal, dielectric covered metal, polystyrene) has been investigated. Plasma ignition causes fluiddynamic instabilities moving in the direction of the jet flow and correlated with the highvoltage pulses: for low pulse repetition frequency (PRF) (\125 Hz), the movement of the turbulent front between two voltage pulses can be tracked, whereas for higher PRF (1,000 Hz) the flow is completely characterized by turbulent eddies in the effluent region, without relevant changes between subsequent voltage pulses. When the jet is impinging on a substrate, turbulent fronts propagate over the surface starting from the gas impinging zone.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
