基于VPM-THINC/QQ模型的波浪高保真模拟

HIGH-FIDELITY SIMULATION OF WAVE PROPAGATION BASED ON VPM-THINC/QQ MODEL

为实现波浪传播的高保真数值模拟,采用包含单元均值和点值(volume-average/point-value method,VPM)的有限体积法求解纳维-斯托克斯方程和具有二次曲面性质和高斯积分的双曲正切函数(THINC method with quadratic surface representation and Gaussian quadrature,THINC/QQ)方法来重构自由面,建立以开源求解库OpenFOAM底层函数库为基础的VPM-THINC/QQ模型.在本模型中添加推板造波法实现波浪的产生功能,采用松弛法实现消波功能,构建高精度黏性流数值波浪水槽.分别采用VPM-THINC/QQ模型和InterFoam求解器(OpenFOAM软件包中广泛使用的多相流求解器)开展规则波的数值模拟,重点探究网格大小和时间步长等因素对波浪传播过程的影响,定量地分析波高衰减程度;为验证本模型的适应性,对长短波进行模拟.结果表明,在相同网格大小或时间步长条件下,VPM-THINC/QQ模型的预测结果与参考值吻合较好,波高衰减较少,且无相位差,在波浪传播过程的模拟中呈现出良好的保真性.本文工作为波浪传播的模拟研究提供了一种高精度的黏性数值波浪水槽模型.

In order to achieve high-fidelity of numerical simulation of wave propagation, an improved finite volume method with volume-average and point-value (VPM) is used to solve the Navier-Stokes equation and the tangent of hyperbola for interface capturing with quadratic surface representation and Gaussian quadrature reconstructs the free surface. The VPM-THINC/QQ model based on OpenFOAM underlying function library is established. The piston wave-making method is added to the current model to realize the wave generation, and the relaxation method is used to realize the wave dissipation. A high-precision viscous numerical wave water tank is built. The numerical simulation of regular waves is carried out by using VPM-THINC/QQ model and interFoam solver (multiphase solver widely used in OpenFOAM software packages) respectively. The effects of grid size and time step on the wave propagation process are investigated mainly. The attenuation degree of wave height is quantitatively compared and analyzed. In order to verify the adaptability of the current model, simulation of long and short waves is carried out. The results show that under the same grid size or time step, the prediction results of the VPM-THINC/QQ model agree well with the theoretical solution compared with the interFoam solver. The wave height has little attenuation and there is no phase difference. It shows high-fidelity of the VPM-THINC/QQ model in the wave propagation process. A high-precision model of viscous numerical wave tank is provided for studying the wave propagation process in this work.