A new lagrangian particle method to describe turbulent flows of fully compressible ideal gases

Abstract

There are several approaches to describe flows with particles e.g. Lattice-Gas Automata (LGA), Lattice-Boltzmann method (LBM) or smoothed particle hydrodynamics (SPH). These approaches do not use fixed grids on which the Navier-Stokes equations are solved via e.g. finite volume method. The flow is simulated using a multitude of particles or particle density distributions, which interacts and due to statistical laws and an even more fundamental approach than the Navier-Stokes equation, the averaged flow variables can be derived. After a short summary of the most popular particle methods the new DMPC (Dissipative Multiple Particles Collision) approach will be presented. The DMPC-model eliminates some of the weak points of the established particle methods and shows high potential for more accurate CFD solution especially in areas where standard CFD tools still have problems (e.g. aero-acoustics). The DMPC-model deals with discrete circular particles and calculates the detailed collision process (micro scale) of several overlapping particles. With thermodynamic, statistical and similarity laws global (large scale) flow variables can be derived. The model is so far 2d and the particles can move in every direction in the 2d plane depending on the forces acting on it. The possible overlap between neighbouring particles and multi-particle interactions are important features of this model. A freeware software is developed and published under www.cfd2k.eu. There the executable, the user guide and several exemplary cases can be downloaded.