Thermal Dynamics of Settling Inertial Particles in a Stably Stratified Turbulent Flow

The effect of settling inertial particles in forced homogeneous and isotropic turbulence, within the Boussinesq approximation, has been studied. An Eulerian-Lagrangian point-particle direct numerical simulation (DNS) approach is employed to simulate a diverse range of particle inertia and settling parameters. We investigate the impact of the particle settling parameter, which can reach values up to 1, as well as the influence of inertia on flow statistics. Our observations indicate that the settling parameter alters the fluid-particle velocity and temperature difference moments, with the effect becoming more pronounced as both particle inertia and thermal inertia increase. All statistics have been compared to the case in which particle settling is neglected. Results are presented for a diverse range of particle Stokes numbers, from 0.1 to 4, with a thermal Stokes number to Stokes number ratio of 6.24, at a Taylor microscale Reynolds number of 128, and a Richardson number of 0.25.