Experimental investigation of the cavitation characteristics of jet pump cavitation reactors with special emphasis on negative flow ratios

The flow characteristics of jet pump cavitation reactors (JPCR) were experimentally investigated for various area ratio and flow ratios varying from the maximum to −1. The focus was on the cavitation area and cavitating flow pattern for low and negative flow ratios using high-speed photography and the pressure change characteristics. This work provides a thorough understanding of the fluid dynamics and structural characteristics during cavitation such as the flow ratio, pressure ratio, area ratio and cavitation area. The results indicate that the pressure ratio has crucial effect on the change of cavitation area in negative flow ratios. The cavitation can be divided into the downstream transport cavitation stage, reflux detention cavitation stage and reverse transport cavitation stage bounded by the transition flow ratios. The flow ratio ranges are given for the various cavitation stages for various area ratios which has a significant impact on the cavitation stage. Reverse transport cavitation will not occur in the JPCR for large area ratios. When the back pressure is higher than the inlet pressure, shear cavitation strengthens significantly leading to violent collapse of the cavity, which is of potential applications as a cavitation reactor.