Development and validation of new cryogenic cavitation model for rocket turbopump inducer

Abstract

A rocket propellant is often used cryogenic fluid such as liquid hydrogen or liquid oxygen, and it is known that a suction performance of turbopump inducer (Fig.1) in cryogenic fluid is improved due to Thermodynamic effect . Thermodynamic effect can be explained by temperature decrease inside a cavity region arising from the latent heat absorption. Although this effect is also to be observed in water cavitation, it becomes more accentuated in cryogenic fluid. In order to properly understand the cavitation performance of the inducer, this thermodynamic effect should not be overlooked. In the present study, cryogenic cavitation model without energy equation was established. During the design phase of an inducer, wall clock time of CFD simulation becomes an important point, therefore, equation number should be small. The present model considers that temperature decrease due to latent heat absorption is analytically estimated. Validation calculations were carried out for blunt head form and hydrofoil for water cavitation and two-dimensional blunt body, Laval nozzle and inducer for cryogenic fluids.