Numerical Investigation of MHD Nanofluid Forced Convection in a Microchannel Using Lattice Boltzmann Method

Abstract

In this paper, flow and heat transfer of water–Al2O3 nanofluid in a two-dimensional microchannel that is under the influence of a uniform magnetic field is investigated. The thermal boundary conditions applied on the channel walls are constant temperature at the lower wall and insulated at the upper one. Lattice Boltzmann method is used to obtain the velocity and temperature fields. The effects of relevant parameters such as the Reynolds number (5–25), the nanoparticles volume fraction (0–4%) and the Hartmann number (0–10) are investigated on heat transfer coefficient and friction factor. The results show that the microchannel heat transfer performance is improved 19% by increasing the Reynolds number from 5 to 25. The magnetic field does not have remarkable effect on the heat transfer coefficient, but increases the friction factor up to 86%. Also, heat transfer coefficient enhances 17% by increasing the nanoparticles volume fraction up to 4%, but the rate of improvement in heat transfer coefficient decreases at higher Reynolds and Hartmann numbers.