基于Fluent的内孤立波质量源造波方法研究

A Study on Mass Source Wave-generating Method of Internal Solitary Waves Based on Fluent

在RNGk-ε湍流模型下,基于Fluent平台中的DEFINE-SOURCE宏,结合KdV与eKdV理论编写相应程序,从粘性不可压缩流体的N-S方程出发,进行了基于质量源造波法的内孤立波数值模拟,并将所得模拟结果与物理实验结果、理论值及速度入口法与平板拍击法数值模拟结果进行了对比和分析。结果表明:质量源造波法所得波形与物理实验结果、理论值及速度入口法与平板拍击法数值模拟结果吻合较好,验证了本文所述质量源造波方法的可行性和有效性,且该方法对振幅水深比小于0.1和大于0.1的内孤立波均具有较好的适用性。此外,质量源造波法避免了动网格的使用、可用于研究速度边界未知的情况、耗时短、效率高、适应性强等优点为进一步研究内孤立波与海洋结构物的相互作用问题提供了一种新的实现方案。

With RNG turbulent model and based on the DEFINE_SOURCE macros of Fluent software platform, corresponding programs were written by combining with the theories of KdV and eKdV. From the Navier-Stokes equation of viscous incompressible fluid, numerical simulations of internal solitary waves were carried out based on mass source method with simulation results analyzed and com- pared with physical experiment results, theoretical values as well as the results obtained with velocityinlet and moving pedal methods. Our trials showed that waveforms obtained with mass source wave method were in good agreement with experimental and theoretical values and the results obtained with velocity-inlet and moving pedal methods, which proved the feasibility and validated the effectiveness of proposed method described in this study, and showed the applicability to those internal solitary waves at ratios of amplitude to water depth 〈 0.1 and 〉 0.1. In addition, this numerical method avoided the use of dynamic grid, thus being appropriate for studying the situations of boundary with unknown velocity. The method established in this study holds the advantages of short time consuming, high efficiency and high adaptability over the available currently, which provided a new approach for studying the interaction between internal solitary waves and marine structures.