Abstract At the booster turbopump exit of a high pressure staged combustion cycle based cryogenic rocket engine, hot gaseous oxygen after driving the booster turbine mixes with subcooled liquid oxygen from the booster pump leading to a complex phenomena of direct contact condensation of hot oxygen gas. The aim of the present investigation is to numerically study the condensation of oxygen vapor jets in subcooled liquid oxygen using a two-fluid two-phase model in the Eulerian framework to understand the mixing process at the booster turbopump exit. The unstable nature of the oxygen plume shapes at cryogenic temperatures have been examined and the stable to unstable transition in an unstable direct contact condensation cycle have been analyzed. A detailed parametric study has been conducted using the Box-Behnken design and suitable correlations are developed for the critical design parameters viz., overall averaged heat transfer coefficient and dimensionless maximum vapor penetration length. Finally, the maximum pressure oscillation amplitudes associated with unstable oscillatory oxygen direct contact condensation are characterized. The results of the present investigation will be helpful in designing experimental set-up for studying the unstable direct contact condensation at cryogenic temperatures and will serve as preliminary guidelines for the design of an oxygen direct contact condenser, which hitherto is unavailable in the open literature.

中文翻译：

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过冷流动液氧中氧气蒸汽射流不稳定振荡​​直接接触冷凝(DCC)的数值研究

摘要 在基于高压分级燃烧循环的低温火箭发动机增压涡轮泵出口处，驱动增压涡轮后的热气态氧与来自增压泵的过冷液氧混合，导致热氧气直接接触冷凝的复杂现象。本研究的目的是使用欧拉框架中的两流体两相模型对过冷液氧中氧蒸汽射流的冷凝进行数值研究，以了解增压涡轮泵出口处的混合过程。已经检查了低温下氧羽流形状的不稳定性质，并分析了不稳定直接接触冷凝循环中稳定到不稳定的转变。使用 Box-Behnken 设计进行了详细的参数研究，并为关键设计参数开发了合适​​的相关性，即总体平均传热系数和无量纲最大蒸汽渗透长度。最后，表征了与不稳定振荡​​氧直接接触冷凝相关的最大压力振荡幅度。本研究的结果将有助于设计用于研究低温下不稳定的直接接触冷凝的实验装置，并将作为氧气直接接触冷凝器设计的初步指南，迄今为止，这在公开文献中是不可用的。最后，表征了与不稳定振荡​​氧直接接触冷凝相关的最大压力振荡幅度。本研究的结果将有助于设计用于研究低温下不稳定的直接接触冷凝的实验装置，并将作为氧气直接接触冷凝器设计的初步指南，迄今为止，这在公开文献中是不可用的。最后，表征了与不稳定振荡​​氧直接接触冷凝相关的最大压力振荡幅度。本研究的结果将有助于设计用于研究低温下不稳定的直接接触冷凝的实验装置，并将作为氧气直接接触冷凝器设计的初步指南，迄今为止，这在公开文献中是不可用的。