Direct Numerical Simulation of Multiphase Flows

Direct Numerical Simulation of Multiphase Flows

Leitung:  P. Wriggers
Team:  B. Avci
Jahr:  2009

Multiphase flows consisting of a continuous fluid phase and a dispersed phase of macroscopic particles are present in many engineering applications. In general, a main task in the study of the particle-laden fluid flow of an application is to make predictions about the system's nature for various boundary conditions, since, depending on the volume fraction and mass concentration of the dispersed phase a fluid-particle system shows quite different flow properties. Unfortunately, often it is impossible to investigate such a system experimentally in detail or even at all. An option to capture and to predict its properties is performing a direct numerical simulation of the particulate fluid. For this purpose, a model approach based on a fictitious domain method is developed in this project. Here, the fluid and the particle phase are treated, respectively, within the framework of the finite element method (FEM) and the discrete element method (DEM). The coupling scheme, which accounts for the phase interaction, is realized at the particle scale. For the computation of the forces that the fluid exerts on a particle an approach is used in which they are determined directly from the flow field in the vicinity of its surface.