Numerical simulation of sloshing with large deforming free surface by MPS-LES method   总被引：1，自引：1，他引：0  

潘徐杰  张怀新  孙学尧 《中国海洋工程》2012,26(4):653-668

Moving particle semi-implicit (MPS) method is a fully Lagrangian particle method which can easily solve problems with violent free surface. Although it has demonstrated its advantage in ocean engineering applications, it still has some defects to be improved. In this paper, MPS method is extended to the large eddy simulation (LES) by coupling with a sub-particle-scale (SPS) turbulence model. The SPS turbulence model turns into the Reynolds stress terms in the filtered momentum equation, and the Smagorinsky model is introduced to describe the Reynolds stress terms. Although MPS method has the advantage in the simulation of the free surface flow, a lot of non-free surface particles are treated as free surface particles in the original MPS model. In this paper, we use a new free surface tracing method and the key point is "neighbor particle". In this new method, the zone around each particle is divided into eight parts, and the particle will be treated as a free surface particle as long as there are no "neighbor particles" in any two parts of the zone. As the number density parameter judging method has a high efficiency for the free surface particles tracing, we combine it with the neighbor detected method. First, we select out the particles which may be mistreated with high probabilities by using the number density parameter judging method. And then we deal with these particles with the neighbor detected method. By doing this, the new mixed free surface tracing method can reduce the mistreatment problem efficiently. The serious pressure fluctuation is an obvious defect in MPS method, and therefore an area-time average technique is used in this paper to remove the pressure fluctuation with a quite good result. With these improvements, the modified MPS-LES method is applied to simulate liquid sloshing problems with large deforming free surface. Results show that the modified MPS-LES method can simulate the large deforming free surface easily. It can not only capture the large impact pressure accurately on rolling tank wall but also can generate all physical phenomena successfully. The good agreement between numerical and experimental results proves that the modified MPS-LES method is a good CFD methodology in free surface flow simulations.  相似文献   

移动粒子半隐式法中核函数适用性研究     

潘徐杰  张怀新  孙学尧 《海洋工程》2010,28(4)

研究了移动粒子半隐式法(MPS法)中核函数的特性。选取溃坝、晃荡和船舶横剖面横摇分别作为不具有边界速度、具有一维边界速度和具有二维边界速度模拟的代表,研究了MPS法中常见五种核函数在上述三种速度边界条件模拟中的适用性。结果表明,在核函数的作用力范围边界时,要求提供适中的作用力,较大的作用力会导致模拟的失败;提供适中作用力的核函数适合于具有一维边界速度的模拟,而提供较小作用力的核函数适合于具有二维边界速度的模拟。  相似文献