Cavitation Instability in Subcooled Liquid Nitrogen Nozzle Flows

Subcooled cryogenic fluids are used in many fields such as a propellant for liquid propulsion rocket systems and a coolant for superconducting systems. However, the fundamental characteristics of subcooled cryogenic cavitating flows have not been clarified. Therefore, a visualization experiment for a cryogenic cavitating flow passing through a converging-diverging nozzle was carried out with liquid nitrogen in the subcooled condition. The results indicate that the cavitation instability is caused by the intersection of the speed of sound in a gas-liquid two-phase flow with the required velocity for cavitation inception and cavitation conservation.