NUMERICAL STUDY OF CAVITATION IN CRYOGENIC FLUIDS

The numerical simulations of cavitation in liquid nitrogen and liquid hydrogen are presented. In order to consider the influence of temperature, the solver control equation including the continuity, momentum and energy equations are adopted, computations are conducted by implementing a Merkle cavitation model and the material property, and the material parameters update with temperature in the flow. A few cases are conducted in liquid nitrogen and hydrogen, and the simulation results are compared with experimental ones. It is found that the thermal effects of cavitation are more obviously in both the liquid nitrogen and hydrogen when the fluid is operating close to its critical temperature. The thermal effect more obviously in liquid nitrogen and hydrogen shows that: the cavity length is shorter; the water vapour volume fraction is decreased and the cavity becomes less distinct. The thermal effect of liquid hydrogen is more distinctly compared with liquid nitrogen due to the difference of the density ratios, vapour pressure and other variable properties of the fluids.