Effects of Surface Roughness on Thermal and Hydrodynamic Behaviors in Microchannel Using Lattice Boltzmann Method

Abstract

The aim of the present study is to use the artificial roughness geometries in order to investigate the thermal and hydrodynamic behaviors in a rough microchannel using the most effective alternative method in micro-flows namely Lattice-Boltzmann Method (LBM). The rough surfaces are configured with triangular, trapezoidal and rectangular roughness elements with a relative roughness height 0~8% of the channel height. To analyze the roughness effects, the friction coefficients in terms of Poiseuille number (Pn), the rate of heat transfer in terms of Nusselt number (Nu) and the mass flow rate have been discussed at the slip flow regime, 0.01 ≤ Kn ≤ 0.10, where Kn is the Knudsen number. Finally, the overall performance has been studied numerically. All of these numerical results for all kind of roughness geometries are compared with smooth microchannel.