Acoustic waves effect on the generation of nitrogen oxides by corona discharge in air

We studied the interaction of acoustic waves with negative corona discharge in air at atmospheric pressure. The application of acoustic waves on the discharge causes a mixing of ambient air with the gas between the electrodes, which results in cooling of the gas in the inter-electrode gap. As a rough indirect indicator of the discharge cooling, we used a concentration of nitrogen oxides generated by the discharge. We chose these oxides because they exhibit antibacterial properties. We showed that for a particular discharge power with increasing amplitudes of acoustic displacements, the concentration of generated nitrogen mono/dioxide decreases, and that this decrease could be attributed mainly to the temperature. We also found that application of acoustic waves on the discharge for a particular power substantially decreases transient spark frequency, increases the magnitude of the streamer onset voltage, and increases the difference between the streamer and spark onset voltage. (paper)