Microchannel heat transfer and dispersion of nanoparticles in slip flow regime with constant heat flux

If the hydrodynamic diameter of a channel is comparable with the mean free path of the gas molecules moving inside the channel, the fluid can no longer be considered to be in thermodynamic equilibrium and a variety of non-continuum or rarefaction effects can occur. To avoid enormous complexity and extensive numerical cost encountered in modeling of nonlinear Boltzmann equations, the Navier–Stokes equations can be solved considering the concepts of slip flow regime and applying slip velocity boundary conditions at the solid walls. In this study, the Navier–Stokes and energy equations for fluid flow in a microchannel in slip flow regime were solved analytically and temperature and velocity profiles were evaluated. The effect of different parameters on heat transfer and dispersion of nanoparticles was discussed. Dispersion of particles due to drag force, Saffman lift force, Brownian forces and gravity force was studied using a Lagrangian approach. The presented results could provide guidelines for heat transfer modeling in nanofluids.