Moving Particle Semi-implicit Method: Fully Lagrangian Analysis of Incompressible Flows

Moving Particle Semi-implicit (MPS) method is based on fully Lagrangian description. Particle interaction models are prepared for differential operators, such as gradient, divergence and Laplacien. Governing equations are transformed to interactions among moving particles. Grids are not necessary. Large deformation of interfaces can be analyzed without grid tangling. Numerical diffusion does not arise because the convection terms are not discretized. Collapse of a water column is calculated by MPS method. Fragmentation and coalescence of water is successfully analyzed. MPS method is applied to wave breaking on slopes. Two modes of wave breaking are in good agreement with experimental data. A gridless convection scheme named Meshless Advection using Flowdirectional Local-grid (MAFL) is developed for arbitrary Lagrangian-Eulerian (ALE) description in combining MPS method. The combined method, MPS-MAFL, enables us to analyze wider range of thermal-hydraulic problems: for example, those involving inflow and outflow boundaries where Eulerian treatment is better. Local concentration of the computing points is easier in MPS-MAFL method. Bubble growth and departure in a nucleate boiling cycle is calculated and the heat transfer agrees well with that of an experiment. S. Koshizuka and Y. Oka 2