Experience using pressure-based CFD methods for Euler–Euler simulations of cavitating flows
Experience using pressure-based CFD methods for Euler–Euler simulations of cavitating flows
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DOI：
10.1016/j.compfluid.2015.01.008
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发表时间：
2015-04
影响因子：
2.8
通讯作者：
S. Yakubov;Thierry Maquil;T. Rung
中科院分区：
文献类型：
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作者：
S. Yakubov;Thierry Maquil;T. Rung
本文介绍了空化两相流模拟中考虑密度变化的压力-速度耦合方法的不同方法。从两种策略得到的结果进行了详细的研究。一个更简单的工程方法相关联的局部密度的变化仅与汽体体积分数的变化计算的空化模型，并假设不可压缩的蒸汽和水相。一个更精细的方法另外考虑了两个单独的流体相的可压缩性。本文讨论了在工程应用中具有重要意义的数值问题，如病态矩阵的出现或空化模型的依赖性。单相验证和确认研究参考了突出的空气动力学基准，即收敛-扩张喷管流和通道中凸起处的流。空化流验证涉及到水翼上的定常流。通过对NACA 0015翼型的非定常空化流场进行数值计算，验证了可压缩流体方法模拟薄板空化和蒸汽空化的优点，包括蒸汽云的溃灭以及激波的形成和传播。结果表明，这两种方法预测的气穴模式非常相似，并且仅当注意塌陷空腔压力波的演变时（例如在侵蚀研究中）才需要可压缩流动模型。
The paper is devoted to different approaches of a pressure–velocity coupling method to account for density variations in cavitating two-phase flow simulations. Results obtained from two strategies are investigated in detail. A simpler engineering approach associated the variations of the local density solely with the changes of the vapor-volume fraction computed by a cavitation model and assumes incompressible vapor and water phases. A more elaborate method additionally accounts for the compressibility of the two individual fluid phases. Numerical issues of significance for engineering applications are discussed in the paper, such as the occurrence of ill-conditioned matrices or cavitation-model dependencies. The single-phase verification and validation study refers to prominent aerodynamic benchmarks, i.e. a convergent-divergent nozzle flow and the flow over a bump in a channel. Cavitating flow validations are concerned with a stationary flow over a hydrofoil. An unsteady cavitating flow over a NACA0015 hydrofoil is computed to demonstrate merits of the implemented compressible fluid method to simulate sheet and vapor cavitation including the collapse of a vapor cloud followed by a shock wave formation and propagation. Results demonstrate that the predicted cavitation pattern of the two approaches are very similar and the compressible flow model is only required when attention is directed to the evolution of pressure waves of the collapsing cavities, e.g. in erosion studies.