FULL WAY COUPLING OF LARGE EDDY SIMULATION FOR PARTICLE-LADEN TURBULENT FLOWS USING NEW DYNAMIC SGS MODELS

Abstract

A new method named Full Way Coupling of Large Eddy Simulation (LES) for particle-laden turbulent flows using two modified dynamic Sub-Grid-Scale (SGS) models and considering particles collision based on a Eulerian-Lagrangian approach was presented. In order to simulate the interactions of SGS components, two new SGS models were introduced: Dynamic Random Walk SGS Model was used to calculate the particles diffusion by fluid SGS component, and the fluid turbulence modification of particle SGS component has been investigated using a proposed Dynamic Fluid-Particles SGS Coupling Model. The advantage of these new SGS coupling models is that the dimensional analysis coefficient of proposed SGS model could be decided by Germano's (1991) dynamic procedure. The effects of inter-particle collision on particles motion were taken into accounts using Direct Numerical Simulation (DNS). Using this Full Way Coupling method, the numerical simulations were performed for downward channel flow at Reynolds numbers of 644 that was identical to the experiments done by Kulick et al. in 1994. The effects of fluid-particles SGS component couplings and inter-particle collisions on solid particles dispersion and fluid turbulence modification in LES for particle-laden turbulent flows were then investigated.