Study of liquid nitrogen cavitation flow

Thermal effects substantially impact the cavitation dynamics of cryogenic fluids. In order to study the cavitation characteristics in cryogenic fluids, numerical simulations of cavitation in liquid nitrogen are presented in this study. The present article focuses on simulating cryogenic cavitation by implementing the modified Kunz cavitation model coupled with energy equation and iterative update of the real fluid properties at local temperatures using CFX software. Computations were conducted on a 2D quarter caliber hydrofoil and an axisymmetric ogive in liquid nitrogen, based on which the cavitation characteristics with thermal effects were explored. The numerical results were obtained and they were agreement with the experimental data basically. The results show that, when the fluid is operating close to its critical temperature, thermal effects of cavitation are more obvious in liquid nitrogen. The cavity length is shortened, the cavity content becomes less and the cavity shows more porous. In the cavity region, the temperature depresses due to absorb the evaporation latent heat, and there is a temperature rise at the cavity rear end attributed to the release of latent heat during the condensation process. It is also observed that the temperature depression due to evaporative cooling is found to be only within 0.5~2.5 K.