火箭推进

诱导轮是决定涡轮泵抗空化能力的关键部件,为了揭示诱导轮内部液氧空化流动特性,建立了基于能量方程源项修正的低温空化数值计算方法,同时耦合了液氧物性随温度变化关系,利用经典低温空化和诱导轮空化试验数据进行了充分验证,对某三叶片诱导轮内部液氧空化流动进行了仿真分析。结果表明:低温介质空化过程中与周围液体存在剧烈的能量交换,但只有一部分空化溃灭释放的热量被传递至周围流场,通过调节能量方程源项中空化溃灭释热比例可使空化区尾部温度场预测精度提升0.5%。对比等温计算,考虑热效应后,液氧空化区范围和内部汽相体积分数大幅减小,对流道的阻塞程度降低,有效延缓了诱导轮扬程断裂。对3种温度下液氧空化流动进行仿真研究,发现液氧温度越高,空化范围越小,同时空化区温降越大,诱导轮空化性能改善也越显著。

Inducer is key component which determinates the anti-cavitation ability of a turbopump. In order to clarify the LOX cavitation flow characteristic inside the inducer, a novel numerical simulation for cryogenic cavitation method has been built based on the correction of energy equation source term, and the relationship between physical properties and temperature variation is coupled. The numerical method has been verified by the classical cryogenic cavitation and the inducer cavitation experimental data. Then, a simulation analysis of cavitation flow inside a three-bladed inducer are conducted, and it is found that: there is strong energy exchange between cavities and the surrounding liquid during the cryogenic cavitation, but only part of the heat released by the cavitation collapse can be transferred to the surrounding liquid. By adjusting the heat release ratio of heat by cavitation collapse in the source term of energy equation, the prediction precision of temperature field near the cavity rear can be improved by 0.5%. Compared with isothermal calculation results, the LOX cavitation area and vapor volume fraction decrease remarkably when the thermal effect is considered, thus the blocking effect to the blade channels decreases either, and the inducer head breakdown is delayed effectively. The simulation study of the LOX cavitation flow at different temperature shows that the higher the liquid oxygen temperature, the smaller the cavitation range, and the larger the temperature drop in the cavitation region, the more significant the improvement of cavitation performance for the induced wheel.

引言
1 研究方法
2 结果与讨论
3 结论

图1 2D翼型计算域和网格细节<br/>Fig.1 Calculation domain of 2D hydrofoil and mesh details

图1 2D翼型计算域和网格细节
Fig.1 Calculation domain of 2D hydrofoil and mesh details

图2 诱导轮计算域<br/>Fig.2 Calculation domain of inducer

图2 诱导轮计算域
Fig.2 Calculation domain of inducer

图3 翼型表面压力、温度分布<br/>Fig.3 Pressure and temperature distribution on the hydrofoil surface

图3 翼型表面压力、温度分布
Fig.3 Pressure and temperature distribution on the hydrofoil surface

图4 诱导轮空化性能<br/>Fig.4 Cavitation performance curves of inducer

图4 诱导轮空化性能
Fig.4 Cavitation performance curves of inducer

图5 诱导轮内部空化形态<br/>Fig.5 Cavitation morphology inside the inducer

图5 诱导轮内部空化形态
Fig.5 Cavitation morphology inside the inducer

图6 等温计算和考虑热效应计算结果对比(σ=0.108, 液氧, 100 K)<br/>Fig.6 Comparison of flow details with and without thermal effect(σ=0.108, LOX, 100 K)

图6 等温计算和考虑热效应计算结果对比(σ=0.108, 液氧, 100 K)
Fig.6 Comparison of flow details with and without thermal effect(σ=0.108, LOX, 100 K)

$图7 不同叶高位置汽相体积分数(σ=0.027, 液氧, 100 K)<br/>Fig.7 Vapor volume fraction at different blade span(σ=0.027, LOX, 100 K)$

图7 不同叶高位置汽相体积分数(σ=0.027, 液氧, 100 K)
Fig.7 Vapor volume fraction at different blade span(σ=0.027, LOX, 100 K)

图8 不同液氧温度诱导轮空化性能<br/>Fig.8 Cavitation performance at different LOX temperatures

图8 不同液氧温度诱导轮空化性能
Fig.8 Cavitation performance at different LOX temperatures

图9 空化区温度分布(σ=0.1)<br/>Fig.9 Temperature distribution inside cavities(σ=0.1)

图9 空化区温度分布(σ=0.1)
Fig.9 Temperature distribution inside cavities(σ=0.1)

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备注

引言

1 研究方法

2 结果与讨论

3 结论

期刊信息