Numerical Assessment of the Thermal Performance of Microchannels with Slip and Viscous Dissipation Effects

In the present paper, a numerical analysis of the performance of microchannels featuring rectangular, trapezoidal, and double-trapezoidal cross-sections is presented. The fully developed laminar forced convection of a Newtonian fluid with constant properties is considered. The non-dimensional forms of governing equations are solved by setting slip velocity and uniform heat flux as boundary conditions. Model accuracy was established using the available scientific literature. The numerical results indicate that viscous dissipation effects led to a decrease in the average Nusselt number across all microchannels examined in this study. The degree of reduction is influenced by the cross-section, aspect ratio and Knudsen number. The lowest average Nusselt number values were observed under continuum flow conditions for all the microchannels investigated.