The Impact of Turbulent Flow on Nanosecond Pulsed Streamer Discharges in Cylinder-Wire Configurations

Streamer discharge generation by nanosecond highvoltage pulses in a cylinder-wire reactor is proven to be an efficient method for air purification [1]. In general, it appears that for this application short rise times and short pulse durations are beneficial. One point that has been overlooked in discussions on the efficiency of cylinder-wire reactors is the impact of fluid dynamics. Simulations have revealed that gas flow properties could have quite an impact on reactor efficiency. The presence - or lack of - turbulence may lead to over-exposure to discharges in certain areas in the reactor while leading to under-exposure in others. In this work, we compare these simulations with experimental work in order to investigate the impact of flow. For the experimental work, we use a 17 kV solid state pulse source that generates pulses with pulse durations down to 100 ns and a rise time of 15 ns. The pulses are applied to a modular reactor system in which we can place inserts that allow flow modification inside the cylinder. The resulting discharges in different flow configurations were investigated with UV spectroscopy and electrical diagnostics to determine ozone generation efficiency. From the measurements, we determined that even though the flow pattern is impacted by the inserts, the resulting efficiency is not. This leads to the hypothesis that the discharges themselves are a leading factor in determining the flow pattern.