Cryogenic cavitation and heat transfer in high-speed liquid hydrogen pump

The cavitation process is accompanied by substantial latent heat absorption and release, a thermodynamic effect that profoundly influences fluid behavior under cryogenic conditions. To address the cavitation challenge in high-speed liquid hydrogen pumps under low-temperature environments, this study incorporated thermodynamic corrections and high-rotational-speed viscous effects into the Zwart–Gerber–Belamri (ZGB) cavitation model to establish a cryogenic cavitation model suitable for high-speed two-phase flow. The reliability and applicability of the modified model were validated by comparing the predicted pressure and temperature-drop distributions against those derived from the original ZGB model and Hord's cryogenic experimental measurements. On this basis, a full-flow-passage geometric model of a high-speed liquid hydrogen pump was constructed to systematically investigate the evolutionary characteristics of cryogenic cavitation within the inducer and impeller under varied flow conditions, as well as the cavitation patterns and temperature distribution within the flow channel under different cavitation numbers. The results demonstrate that the flow rate is positively correlated with the cavitation intensity, with the backplate clearance (span = 0.2) identified as the most sensitive to flow variations. Cavitation initiates at the leading edge of the blade suction side and gradually extends toward the trailing edge and blade tip. A lower cavitation number corresponds to a stronger temperature gradient, with local temperatures decreasing to approximately 16 K, while the latent heat released during bubble collapse forms localized high-temperature zones. Thermodynamic effects significantly suppress high-frequency pressure pulsations during the critical cavitation stage and promote the transition from steady cavitation to an intermittent collapse process while also intensifying low-frequency pressure pulsations under severe cavitation conditions. This study elucidates the influence mechanisms of thermodynamic effects on cavitation severity, pressure pulsation behavior, and internal flow conditions, providing a theoretical foundation for cavitation suppression in liquid hydrogen pumps and stability optimization in cryogenic propulsion systems.