PArallel, Robust, Interface Simulator (PARIS)

PARIS (PArallel, Robust, Interface Simulator) is a finite volume code for simulations of immiscible multifluid or multiphase flows. It is based on the “one-fluid” formulation of the Navier–Stokes equations where different fluids are treated as one material with variable properties, and surface tension is added as a singular interface force. The fluid equations are solved on a regular structured staggered grid using an explicit projection method with a first-order or second-order time integration scheme. The interface separating the different fluids is tracked by a Front-Tracking (FT) method, where the interface is represented by connected marker points, or by a Volume-of-Fluid (VOF) method, where the marker function is advected directly on the fixed grid. PARIS is written in Fortran95/2002 and parallelized using MPI and domain decomposition. It is based on several earlier FT or VOF codes such as FTC3D, SURFER or GERRIS. These codes and similar ones, as well as PARIS, have been used to simulate a wide range of multifluid and multiphase flows.PARIS（PArallel, Robust, Interface Simulator，即并行鲁棒界面模拟器）是一款用于非混溶多流体或多相流数值模拟的有限体积法（finite volume）求解程序。该程序基于纳维-斯托克斯方程（Navier–Stokes equations）的单流体控制方程形式，将不同流体视为具有可变物性的单一介质，并将表面张力作为奇异界面力引入其中。流体控制方程在规则结构化交错网格上求解，采用显式投影法，并搭配一阶或二阶时间积分格式。不同流体间的界面可通过前沿跟踪法（Front-Tracking，简称FT）进行追踪：该方法通过连通的标记点表征界面；也可采用流体体积法（Volume-of-Fluid，简称VOF），直接在固定网格上对流输运标记函数。PARIS采用Fortran95/2002语言编写，并通过消息传递接口（Message Passing Interface，简称MPI）与区域分解法实现并行化。该程序基于多款早期的前沿跟踪法或流体体积法代码，例如FTC3D、SURFER以及GERRIS。上述代码及同类程序，包括PARIS在内，已被广泛应用于各类多流体与多相流的数值模拟工作。