Nucleation effects on modeling of cavitating flows

The aim of this investigation is to implement a cavitating flow model taking into account the nucleation for both water and cryogenic fluids, in particular hydrogen. In this paper we re-examine previously developed cavitation models, used for water liquid, including thermal effect for simulations of cryogenic fluids and transport equation for the bubble number. Thermal effects substantially impact the cavitation dynamics of cryogenic fluids. Different numerical cavitation models, based on different physics of mass exchange between liquid and vapor phases, and taking into account the nucleation, were used to simulate the flowfield in internal flow. The transport equation for bubble number is solved in conjunction with the mass and momentum conservation. Performances of the reported cavitation models are tested, comparing the predicted pressure with the experimental data, with non-cryogenic and cryogenic fluids. For non-cryogenic the phase change during rapid depressurization of water have been studied and the role of vapor bubbles nucleation and growth and the effect on the system fluid dynamics were modeled. For cryogenic fluid the cavitation phenomena of liquid hydrogen flowing in a Venturi has been investigated and the results have been compared with experimental data