Electrical and spectroscopic analysis of mono- and multi-tip pulsed corona discharges in air at atmospheric pressure

Abstract

This work is devoted to the analysis of experimental results obtained in dry air at atmospheric pressure in a positive point-to-plane corona discharge under a pulsed applied voltage in the cases of anodic mono-and multi-tips. In the mono-tip case, the peak corona current is analysed as a function of several experimental parameters such as magnitude, frequency and duration of pulsed voltage and gap distance. The variation of the corona discharge current is correlated with the ozone production. Then in the multi-tip case, the electrical behaviour is analysed as a function of the distance between two contiguous tips and the tip number in order to highlight the region of creation active species for the lowest dissipated power. Intensified charge-coupled device pictures and electric field calculations as a function of inter-tip distance are performed to analyse the mutual effect between two contiguous tips. The optical emission spectra are measured in the UV-visible-NIR wavelength range between 200 nm and 800 nm, in order to identify the main excited species formed in an air corona discharge such as the usual first and second positive systems with first negative systems of molecular nitrogen. The identification of atomic species (O triplet and N) and the quenching of NOγ emission bands are also emphasized.

Electric and Spectroscopic Studies of Pulsed Corona Discharges in Nitrogen at Atmospheric Pressure

“…As we have seen in the previous paper [12], we mention the presence of several peaks in the pulse current. First and last peak (opposite sign), superposes with the rising and lowering phase of the applied voltage pulse.…”

“…This space charge current appears very early in comparison with the result obtained in dry air [12], because of the absence of the attachment process in the pure nitrogen case. The critical size of the avalanche that allows the propagation of the streamer corona is reached very quickly in the case of nitrogen (3 ns under our experimental conditions).…”

“…Schematic overview of our measurement set-up that we have already referred in our previous work [12] [13] is given in Figure 1. Corona discharges are generated under a positive pulsed high voltage, by using point plane arrangement in a sealed cell at atmospheric pressure.…”

“…The means used to record our measurement are those that we used in our previous work [12]. Then we give a different images recorded by an ICCD camera to see the development of the discharge in the inter-electrode space, showing different instants corresponding to the propagation of streamers in the gap distance.…”

Electro-hydrodynamics and kinetic modelling of polluted air flow activated by multi-tip-to-plane corona discharge

“…This assumption can be supposed valid since it was shown in restricted conditions (i.e., using pulse voltage conditions, which discharges presenting branching structure) that the mutual effects between two adjacent discharges vanish if the intertip distance is larger than the inter-electrode gap. 30 In our case, with DC voltage condition and mono-filamentary discharges, the inter-tip and inter-electrode distance is of the same order of magnitude (5 mm versus 7 mm).…”