Direct Numerical Simulation of Turbulent Flow and Heat Transfer in a Particle-Laden Turbulent Channel Flow

Abstract

Direct numerical simulation (DNS) is carried out to investigate the impact of solid particles on heat transfer in a plane channel flow. For comparison, two corresponding DNSs of unladen channel flow without the influence of particles are also performed. The numerical simulation of the particle-laden case adopts the two-way coupled Eulerian-Lagrangian computational model, which enables us to consider the momentum transfer between the two phases i.e., discrete particles and the continuous fluid phase. The existence of the particles leads to an increase in the mean temperature, the root mean square of temperature fluctuation, and the streamwise turbulent heat flux within the core region. Moreover, particles have an influence on the correlation between velocity and temperature fields. When comparing the heat transfer of particle-laden channel flow and the corresponding unladen channel flow, it is found that the difference in heat fluxes is rooted in the change of the rms of the vertical velocity and the temperature fluctuations. The impact of particles on the turbulent heat flux transport is significant in the vicinity of the wall, whereas within the core region the impact of particles is relatively small.

Keywords: Heat Transfer, particle, Channel Flow, two-way coupled, Eulerian-Lagrangian