Positive corona discharge of rod-plate electrodes in high-speed airflow

Abstract

The characteristics of positive corona discharge of rod electrode in high-speed airflow are studied in this paper. The experiments were carried out in a wind tunnel with a maximum flow speed of 100 m/s in a dark room. The discharge voltage and current were recorded and the corona patterns were captured by a digital single lens reflex (DSLR) camera during the experiment. A discharge transition in rod electrode from streamer corona to mixed streamer-glow corona, and finally to stable glow discharge was observed with the voltage increased. The increase of airflow speed resulted in a decrease of each corona inception voltages. The streamers will be suppressed and shifted towards the upwind side, while the glow layer will be promoted and shifted towards the downwind side in low and upwind side in high voltages. The glow corona current and the voltage show a quadratic function and the higher the airflow speeds, the bigger the coefficient of square of voltage. The distributions of peaks, pulse widths and interval times of streamer pulses were analysed, showing good correspondence with the streamer images. The measurements were explained by combining particle transport and local air pressure distribution.