弱可压缩移动粒子半隐式方法对溃坝溢流问题的数值模拟

Numerical Simulation of Dam Break Flows by Using WC-CMPS Method

无网格粒子法(拉格朗日法)是计算流体力学领域最新一代的计算方法。由于不需要生成网格,无网格粒子法能够模拟任意形状的界面及其变形和碎裂,尤其适用于计算如溃坝溢流及波浪破碎等具有复杂自由表面运动的流体力学问题。其中,光滑粒子流体动力学方法(SPH)和移动粒子半隐式法(MPS)是无网格计算方法的典型代表。采用基于MPS法的修正弱可压缩移动粒子半隐式法(weakly compressible corrected moving particle semi-implicit method)构建了用于求解自由表面流问题的数值计算模型,并用于模拟干床面与湿床面上的溃坝溢流问题。计算结果与实验结果的对比分析表明,采用基于WCCMPS无网格法建立的数值计算模型对干、湿床面上溃坝溢流的溢流形态、水柱高度以及波前速度等均给出了良好的计算结果。

Mesh-free particle （Lagrangian） methods such as moving particle semi-implicit （MPS） method are the latest generation of numerical techniques in the field of computational fluid dynamics. Due to their mesh-free and Lagrangian natures, these methods are capable of simulating free surface flow problems of very large interfacial deformations and fragmentations with no numerical diffusions involved. Aim at modeling the transient dam break flows over both dry bed and wet bed, the weakly compressible corrected MPS （WC-CMPS） method is used. The established numerical model is firstly validated through comparison of the calculated and experimental results for dam break flows over a dry bed, and then is applied to the dam break flow problems with shallow and deep ambient water depths. The developed WC-CMPS numerical model can give good representation for the propagation of dam break flows including water column dropping speeds and wave front velocities.