Nonlinear algebraic Reynolds stress model for two-phase turbulent flows laden with small heavy particles

Abstract

The purpose of the study is to present an explicit self-consistent algebraic Reynolds stress model (ARSM) for two-phase turbulent flows combined with diffusion-inertia model (DIM). The modulation of turbulence by small heavy particles whose diameter is not greater than the Kolmogorov length scale is considered. The volume concentration of dispersed phase is assumed to be sufficiently small so that inter-particle collisions can be neglected; however, the mass concentration is fairly large (ρp≫ρf). Calculations were performed for turbulent flow in a vertical tube and turbulent flow past a backward-facing step. It was shown that the suggested turbulence model correctly predicts anisotropy of velocity fluctuations and the turbulence modulation by particles. In the presence of small particles turbulence of the flow in a vertical tube is attenuated. The level of turbulence attenuation is increased with increasing particles mass loading and decreased with increasing particle response time. In turbulent flow past the backward-facing step regions with attenuating and enhancing turbulence are observed.