Heat Transfer Characteristics between Microparticles and Fluids in a Microchannel

Abstract

Microparticle suspensions are prevalent in both natural and industrial environments, playing a crucial role in various processes. The heat transfer characteristics between particles and fluids are critical to many of these processes. This study employs the Arbitrary Lagrangian-Eulerian finite element method to simulate and analyze the particle dynamics and fluid–solid heat transfer characteristics within a microchannel, aiming to determine fluid–solid heat transfer characteristics based on the average temperature of particles. The effects of five factors (particle thermal conductivity, specific heat capacity, fluid Reynolds number, particle diameter, and initial particle position) were comparatively analyzed. The results indicate that particles in a laminar microchannel reach a self-equilibrium position under the combined action of fluid shear gradient and wall lift force, with particle size being the primary influencing factor. The shear effect of the fluid causes the particle to rotate, thereby enhancing the convective heat transfer between the particle and the fluid. The Reynolds number also significantly impacts this process. Additionally, thermal conductivity, specific heat, particle size, and position can influence the fluid–solid heat transfer characteristics by altering the internal temperature distribution of the particle. We derived an expression for the Nusselt number using a dimensionless analysis method, which describes the heat transfer between the particle and fluid based on the average temperature of the microparticle.