基于光滑粒子流体动力学方法的溃坝水流模拟

受全球气候变暖的影响，由极端天气引发的类似溃坝等问题发生的概率大大增加，深入研究溃坝水流的水动力特性势在必行。在分析光滑粒子流体动力学基本原理的基础上，提出了一种改进的边界处理方法，即将接近壁面的流体视为层流，在耦合动力边界附近引入层流黏性近似边界层理论。采用该方法对溃坝水流进行数值模拟，将SPH数值模拟得到的外轮廓、自由液面高度以及压力与实验结果进行了比较和分析。结果表明：改进的边界处理方法较完整地得到了水流与壁面相互作用而产生的多种复杂的物理现象，其外部轮廓与实验非常吻合；自由表面融合过程中液面间冲击的能量耗散会导致融合后的液面高度存在一些差异；不同监测点处压力随时间的变化基本落在置信区间之内。数值模拟结果与实验结果吻合度较高，验证了改进方案的可靠性和计算结果的准确性。

Simulation of dam-break flow based on smoothed particle hydrodynamics

Under the influence of global warming, the probability of natural disasters such as dam-break problems caused by extreme weather greatly increase, so it is imperative to study the hydrodynamic characteristics of dam-break flow. Based on the study of the basic principles of smooth particle hydrodynamics, an improved boundary processing method was proposed. In this method, the fluid close to the wall was regarded as laminar flow, and the laminar viscosity approximate boundary layer theory was applied near the coupled dynamic boundary. This method was used to simulate the dam-break flow, then the outer contour, free surface level and the change of pressure with time obtained by SPH numerical simulation were compared with the experimental results. The results showed that the improved boundary treatment method has obtained a variety of complex physical phenomena caused by the interaction between water flow and wall surface, the outer contour was in good agreement with the experiment. Due to the energy dissipation problem of liquid surface impact during free surface fusion, there was some difference in the height of the liquid level after the fusion; the change of pressure with time at different monitoring points basically fell within the confidence interval. The numerical simulation results were in good agreement with the experimental results, which verified the reliability of the improved scheme and the accuracy of the calculated results.