Kinetic energy balance in turbulent particleladen channel flow
Abstract
The present study investigates the influence of particle additives on the transfer, conversion, and dissipation of kinetic energy (KE) of a turbulent gassolid channel flow. We derived the equations of KE, meanflow KE, and turbulent KE (TKE) of the particleladen flow and further performed twoway coupled direct numerical simulations of channel flow laden with fourmillion particles with Stokes number St = 30 (corresponding to a mass loading ratio of around one) with an EulerianLagrangian approach. We found that, in the unladen flow, more than half of the input energy is directly dissipated in the mean flow, whereas the rest is converted to maintain the turbulence. By contrast, in the laden flow, both mean dissipation and energy supply are comparable with the unladen flow. However, the turbulence production is greatly reduced in the particleladen flow. Another sink term due to the presence of the particlefluid interactions corresponds to the rest loss of the total energy supply. The results reveal the particleinduced redistribution of mean KE, which is transferred from the mean flow to particles in the channel core, whereas the flow gains energy from particles in the nearwall region. In total, there is a loss of the meanflow energy due to the presence of the inertial particles. Regarding TKE balance, the particles, gaining energy from the mean flow, transfer the energy to the fluid across the channel, which contributes around one third of the TKE source. The present results provide a general picture of KE balance of a particleladen channel flow.
 Publication:

Physics of Fluids
 Pub Date:
 July 2020
 DOI:
 10.1063/5.0012570
 Bibcode:
 2020PhFl...32g3307P