基于输运方程类空化模型的通气空泡流数值模拟

Numerical Simulation of Ventilated Cavitating Flow Based on Cavitation Model Solving Transport Equations

超空泡流动涉及多相、相变、湍流、可压缩性和非定常特性等复杂情况,亟待发展相应的精细数值模拟方法和计算软件。本文基于均质平衡流理论和输运方程类空化模型,提出了复杂气、汽、水多相的通气空泡流数学模型,采用有限体积方法和SIMPLE算法,建立了求解混合介质的雷诺平均N-S方程、湍流方程、各组分质量分数输运方程的数值模拟方法,自主开发了相应的三维计算程序。模拟了绕圆盘的轴对称通气超空泡流,计算结果与经典的近似公式、半经验公式及试验数据吻合良好,验证了数学模型和数值计算方法能够正确预报通气空泡流场的基本空泡形态和流场动力特性。

Supercavitating flow was a very complex hydrodynamics problem relating to multiphase flow, phase change, turbulence, compressibility and unsteady characteristics. In order to predict the cavitating phenomena, the accurate numerical method and software are required. Based on the homogenous equilibrium flow assumption and cavitation model solving species transport equations, a mathematical model for the prediction of ventilated cavitating flow of gas, vapor and liquid was presented. A numerical approach was establiched, in which the Finite Volume Method and SIMPLE algorithm were applied to discretize and solve the mixture Reynolds-Averaged N-S equation, turbulent equations and constituent mass fraction equations. A 3D code was developed here. The ventilated supercavitating flow over an axisymmetric disk was calculated. The results are good agreement with the approximation solutions, emprical value and experimental data. It indicated that the mathematical model and numerical algorithm are valid for predicting the cavity morphology and hydrodynamics characteristics of flow field.