Investigation of the cavitation model in an inducer for water and liquid nitrogen
Investigation of the cavitation model in an inducer for water and liquid nitrogen
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DOI：
10.1177/0954406219869980
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发表时间：
2019-08
期刊：
影响因子：
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通讯作者：
Yuqiao Zhang;Xiao-dong Ren;Yan Wang;Xue-song Li;Yu Ito;C. Gu
中科院分区：
文献类型：
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作者：
Yuqiao Zhang;Xiao-dong Ren;Yan Wang;Xue-song Li;Yu Ito;C. Gu
汽蚀现象普遍存在于诱导轮等水力机械中。由于制冷剂具有复杂的热力学性质，其内部发生的汽蚀现象十分复杂。计算流体力学可以提供相对精确的预测水。然而，现有的计算流体动力学方法可能无法精确地模拟制冷剂空化。本文对诱导轮内液氮和水中的四种主要空化模型进行了计算流体动力学模拟。在这项工作中分析了四种不同的空化模型，全空化模型，昆兹模型，Zwart-Gerber-Belamri，和Schnerr & Sauer。并通过实验验证了计算流体力学模拟结果，保证了空化模型在两种液体中的适用性。对水和液氮中的空化现象进行了对比分析。四种空化模型均能较好地预测水中的空化，但Zwart-Gerber-Belamri模型和Schnerr & Sauer模型对叶尖涡空化的预测能力也较强。结果表明，在不改变模型常数的情况下，全空化模型适用于液氮空化的数值模拟。在液氮空泡模拟中，需要对其他模型的经验常数进行调整。全空化模型在各种液体中具有很高的鲁棒性。Schnerr & Sauer模型通过采用不同的经验常数可以获得最佳的结果。此外，诱导轮在液氮中的性能优于在低空化数区的水，因为在液氮中的水头系数随着空化数的减小而平稳地下降。
Cavitation commonly occurs in the hydraulic machineries like inducers. Cavitation happening in the cryogens is sophisticated due to their complicated thermodynamic properties. Computational fluid dynamics could provide relatively precise prediction for water. However, existing computational fluid dynamics methods may fail to simulate the cryogens cavitation precisely. This study presents a computational fluid dynamics simulation of four major cavitation models in both the liquid nitrogen and the water in an inducer. Four different cavitation models analyzed in this work are full cavitation model, Kunz model, Zwart–Gerber–Belamri, and Schnerr & Sauer. And the computational fluid dynamics simulation results are verified by the experiment to ensure the cavitation model's applicability in both liquid. Comparison of cavitation in water and liquid nitrogen is conducted and analyzed. The four cavitation models can predict cavitation in water, but the Zwart–Gerber–Belamri model and Schnerr & Sauer model also feature high capability to predict tip vortex cavitation. The results show that the full cavitation model is suitable for simulating the liquid nitrogen cavitation without changing of the model constants. The empirical constants of the other models should be adjusted in the liquid nitrogen cavitation simulation. Full cavitation model features high robustness in various liquids. The Schnerr & Sauer model can achieve the best results by adopting different empirical constants. In addition, the inducer performs better in the liquid nitrogen than water at low cavitation number regime as the head coefficient drops smoothly in liquid nitrogen with decreasing cavitation number.