修正SPH方法在自由表面模拟中的应用

对传统光滑粒子动力学(SPH)方法进行修正,提出了一种密度初始化方法,同时采用一种新的固壁边界处理方法,模拟溃坝问题。通过液滴旋转和无透空块体溃坝问题的模拟验证了修正SPH方法的有效性和在自由表面模拟中的准确性,分析了密度初始化对流动的影响;数值结果表明,修正SPH方法提高了数值计算的精度和稳定性。最后应用修正SPH方法模拟了有透空块体和挡板紧挨水柱的溃坝现象,比较了有无透空块体两种情况下右端直墙上压力变化情况,结果表明,透空块体可使右端直墙上的压力减小,有无挡板、挡板位置和水柱长高比对溃坝现象有重要影响。

Application of the Modified SPH Method to the simulation of free surface

The standard SPH method was modified and implemented to simulate the dam-break by proposing a density re-initialization method,presenting a new treatment of solid walls.The validity of the modified SPH method and its application to free surface are verified by simulating the stretch of the liquid drop and dam-break without a perforated block,the effect of density re-initialization on the flow was analyzed.Results show the accuracy and stability of the standard SPH are improved by the modified SPH method.At last,the dam-break with a perforated block and with a baffle board next to the fluid are simulated by the modified SPH method,comparing the pressure distribution on the upright wall with and without the perforated block.Numerical results show that the perforated block can decrease the value of the pressure on the upright wall; having or not having a baffle board,the aspect ratio of the water column and the location of the baffle board have an important effect on the phenomena of dam-break.