Cavitation is a severe problem in rocket turbopumps. As for turbopumps with liquid oxygen, it exhibits notable thermodynamic effects during cavitation, leading to complex flow characteristic. In this study, to assess the influence of thermodynamic effects on the cavitation flow in a liquid oxygen turbopump, the entire flow passage was numerically simulated using the shear stress transport k–ω turbulence model and a thermodynamic model based on the Zwart–Gerber–Belamri cavitation model to couple the physical parameters with temperature. The numerical schemes were validated using available experimental data. Numerical results show that cavitation primarily occurs at the leading edge of the suction surface of the inducer inlet and at the head of the central blades of the impeller inlet. The thermodynamic effects notably decrease the vapor-phase volume fraction of the cavitation zone at the low cavitation number of $\sigma \text{=}0.07$, but increases it at high cavitation numbers. Moreover, the hydraulic loss in the turbopump was mainly distributed in the impeller-inducer and diffuser. A novel entropy analysis reveals that the thermodynamic effects reduced the dissipation losses generated by the velocity gradient and increased the hydraulic losses induced by the temperature gradient in the wall region. The present study can provide a theoretical reference for improving the hydraulic-instability induced cavitation flow in liquid oxygen rocket turbopumps.

空化是火箭涡轮泵中的一个严重问题。对于带有液态氧的涡轮泵，它在气蚀过程中表现出显着的热力学效应，从而导致复杂的流动特性。在这项研究中，为了评估热力学效应对液氧涡轮泵中空化流的影响，使用剪切应力传递k–ω对整个流道进行了数值模拟。湍流模型和基于Zwart-Gerber-Belamri空化模型的热力学模型，以将物理参数与温度耦合。使用现有的实验数据验证了数值方案。数值结果表明，气蚀现象主要发生在进气口吸气面的前缘和叶轮进气口中央叶片的头部。热力学效应显着降低了低空化数时空化区的气相体积分数。$\sigma \text{=}0.07$，但在高空化数时会增加它。此外，涡轮泵中的水力损失主要分布在叶轮-诱导器和扩散器中。一种新颖的熵分析表明，热力学效应减少了壁区域中由速度梯度产生的耗散损失，并增加了由温度梯度引起的水力损失。本研究可为改善液氧火箭涡轮泵中水力不稳定性引起的空化流动提供理论参考。