Inertial migration of a neutrally buoyant circular particle in a planar Poiseuille flow with thermal fluids

Abstract

This work presents an extensive numerical study on the inertial migration of a neutrally buoyant circular particle in a planar Poiseuille flow with thermal convection using the lattice Boltzmann method. The numerical analysis confirms that, once the channel Grashof number Gr reaches a critical value Grc, the particle lateral equilibrium position transits from above the centerline to below. Moreover, the critical Grashof number Grc depends on the channel Reynolds number and the particle-to-channel size ratio. A force scaling analysis is performed, from which a unified Grashof number Gr* is introduced to consider the synergetic effects of thermal convection and particle size. In addition, it is also found that the occurrence of equilibrium position transition is not sensitive to the initial conditions, but the exact transition point depends on the initial conditions, such as the initial position of the particle and the fluid flow state.