The study on the sedimentation of solid particle influenced by thermal convection using direct numerical simulation

Based on the study of isothermal inert particlesedimentation, the Arbitrary Lagrangian-Eulerian technique was used to solvethe problem of solid particle sedimentation with thermal convectionincluding the energy equation, according to varying the solid-fluid densityratio, that is, the particles settle in different Reynolds number. Theresults show that the thermal convection induces the variety of flow fieldand asymmetry. While setting in hot fluid, the direction of thermalconvection is the same as that of particle sedimentation, and there arevortex shedding arisen by thermal convection. During the sedimentation ofhot particle in the cold fluid, the warm wake forms a strong upward thermalplume. With the increasing of Reynolds, the setting particles undergo threestages: steady motion with and without overshoot; weak and strongoscillations, and irregular oscillations.