Numerical and Experimental Study on the Cavitating Flow Characteristics of Pressurized Liquid Nitrogen in a Horizontal Rectangular Nozzle

摘要

The thermodynamic effect on cryogenic cavitating flow characteristics of pressurized liquid nitrogen in a horizontal rectangular nozzle is precisely investigated by numerical analysis based on an unsteady thermal nonequilibrium two-fluid model and by flow visualization measurement. According to the numerical and experimental study, the sufficiently useful results are proposed to realize the further development and high performance of a type of cryogenic two-phase cooling system. It is numerically and experimentally found that the inception of cryogenic cavitation occurs and the cavity grows in the vicinity of the wall surface of the inlet throat section. It is also found that the continuous process and behavior of cavitation inception, cloud cavity growth, and gas phase diffusion behavior with time in pressurized liquid nitrogen are dominated not only by several additional forces in the gas-phase momentum equation, but also by the thermodynamic effect that acts on the cavitation bubbles due to the inherent properties of cryogenic fluid. Especially under conditions of the same temperature and same aspect ratio of the cloud cavity, similar generating behavior of cavitation can be often found in the high Reynolds number region in spite of large cavitation number.