Propagation Characteristics of Pressure Wave in Cylindrical Reactor Induced by Underwater Pulsed Arc Discharge

Abstract

Underwater pulsed arc discharge is a promising method for the inactivation of sewage microorganisms. Strong pressure wave plays an important role in the deactivation process. Researchers have conducted numerous studies on it, but there has not been a comprehensive study on its propagation in specific reactor. To achieve the industrial application of underwater pulsed arc discharge on sewage disinfection, this article has conducted a detailed study on the propagation of pressure wave in a cylindrical reactor based on experiments and numerical simulations. Several important conclusions are obtained through experiments. The pressure wave consists of three initial pulses generated by the cavity and their reflected waves. It spreads in the reactor at an average speed of 1655 m/s. The attenuation coefficient of the first initial pressure amplitude is 0.65 as the propagation distance increases. In addition, the maximum pressure amplitude decreases with increasing propagation distance, the attenuation coefficient of which is 0.93. The maximum pressure amplitude is always greater than 1.04 times the first maximum pressure amplitude. The following conclusion is obtained by simulation. When the propagation distance is 370 mm, the diameter of the reactor is reduced by 1/2, and the first maximum pressure amplitude will increase by 2.1 times. These results help further understand the distribution of pressure wave in the reactor and provide better guidance for the design of reactor.