基于大涡模拟的移动粒子半隐式算法

移动粒子半隐式方法(MPS)是一种粒子方法,多用于模拟带有自由表面的不可压缩流动。工程实际中的自由表面流动往往是复杂的湍流流动,本文借鉴网格类方法的亚格子应力模型发展了基于Smagorinsky模型的亚粒子应力模型,并将其耦合到MPS方法中,实现了基于大涡模拟的MPS方法并用于研究自由表面湍流问题。为了提高计算的准确性和稳定性,SPS模型中出现的一阶导数项采用最小二乘法拟合得到,SPS项采用显式算法进行计算。使用这一算法模拟了溃坝问题,结果表明,采用亚粒子应力模型的模拟结果与实验的吻合程度明显提高。

Moving Particle Semi-Implicit Method Based on Large Eddy Simulation

The Moving Particle Semi-implicit Method(MPS) is capable of simulating the incompressible free surface flow.Considering most flows in engineering are complicated turbulent flows,the large eddy simulation is introduced into the MPS method.Taken idea from the sub-grid stress in the LES,a similar sub-particle stress based on the widely-used Smagorinsky model is introduced into the MPS method.The first order derivative in the Smagorinsky model is discretized by the least square method to improve the accuracy and stability of the algorithm,and the sub-particle stress is solved in the explicit part of MPS.The results of the dam breaking problem simulated by the developed method are in good agreement with the experimental ones.