数值模拟两相汽蚀流动的新模型和算法

提出了数值模拟两相汽蚀流动现象的新汽蚀模型和算法.提出的汽蚀模型和算法耦合了考虑紊流粘性效应的Reynolds-Averaged Navier-Stokes方程求解方法,可以自动模拟空泡起始点、空泡长度和汽蚀空泡形状.在流场计算和界面修正的迭代计算过程中,跟踪并得到液相/气相界面.数值模拟了圆锥形圆柱体和半球形圆柱体在不同汽蚀系数下的汽蚀流动现象,得到了与实验值完全吻合的数值模拟结果,并且与已发表的数值研究结果进行了比较.计算结果表明提出的汽蚀模型和算法能够有效地模拟汽蚀流动中的气泡界面和气泡长度,汽蚀模型和算法的正确性和实用性得到了相应的验证.

A Model for Two-Phase Cavitation Flows

An algorithm is developed for the flow field in a two-phase cavitation region.The algorithm is implemented in a viscous calculation based on a Reynolds-Averaged Navier-Stokes(RANS) equation solver considering the effect of turbulence.A prior solution of wall detachment point and bubble length is not required.They are simulated by a cavitation model.The liquid/vapor interface is tracked and obtained by an iteration of flow field and interface updating.The algorithm is well validated with a comparison of computational and experimental data available for external flows of a cone/cylinder body and a hemisphere/cylinder body.The liquid/vapor interface shape and bubble length are calculated.The pressure coefficient distributions obtained along the cavitation bubble surface agree well with experimental results.The feasibility and accuracy of the algorithm are illustrated.