A large eddy simulation model for two-way coupled particle-laden turbulent flows

TL;DR

This paper introduces a novel LES modeling framework for particle-laden turbulent flows that captures bidirectional interactions between particles and fluid at multiple scales, improving accuracy over existing models.

Contribution

The framework uniquely models both the influence of subgrid-scale velocities on particles and the particles' effect on turbulence, including turbulence modulation and unresolved particle motion.

Findings

Good agreement with DNS for particle pair separation

Accurately captures particle clustering behavior

Models changes in subgrid-scale kinetic energy due to particles

Abstract

In this paper we propose a new modeling framework for large eddy simulations (LES) of particle-laden turbulent flows that captures the interaction between the particle and fluid phase on both the resolved and subgrid-scales. Unlike the vast majority of existing subgrid-scale models, the proposed framework does not only account for the influence of the sugrid-scale velocity on the particle acceleration but also considers the effect of the particles on the turbulent fluid flow. This includes the turbulence modulation of the subgrid-scales by the particles, which is taken into account by the modeled subgrid-scale stress tensor, and the effect of the unresolved particle motion on the resolved flow scales. Our new modeling framework combines a recently proposed model for enriching the resolved fluid velocity with a subgrid-scale component, with the solution of a transport equation for the subgrid-scale kinetic energy. We observe very good agreement of the particle pair separation and particle clustering compared to the corresponding direct numerical simulation (DNS). Furthermore, we show that the change of subgrid-scale kinetic energy induced by the particles can be captured by the proposed modeling framework.