Flip: A low-dissipation, particle-in-cell method for fluid flow

Abstract

The FLIP (Fluid-Implicit-Particle) method uses fully Lagrangian particles to eliminate convective transport, the largest source of computational diffusion in calculations of fluid flow. FLIP is an adaptation to fluids of the implicit moment method for simulating plasmas, in which particles carry everything necessary to describe the fluid. Using the particle data, Lagrangian moment equations are solved on a grid. The solutions are then used to advance the particle variables from time step to time step. An adaptive grid and implicit time differencing extend the method to multiple time and space scale flows. Aspects of FLIP's properties are illustrated by modeling of a confined eddy, a Rayleigh-Taylor, an unstable subsonic stream, and a supersonic jet. The results demonstrate FLIP's instability applicability to hydrodynamic stability problems where low dissipation is crucial to correct modeling.