Numerical Simulation of Nanofluid Conjugate Heat Transfer in 2D Microchannel under the influence of Transverse Magnetic Field: influence of Nanoparticle Diameter, Reynolds Number and viscous dissipation

In the present study, the effect of viscousdissipation on the flow and conjugate heat transfer of water-alumina nanofluid in a two-dimensional microchannel under the influence of a magnetic field is investigated, using the incompressible lattice Boltzmann method.The upper wall of the microchannel is insulated and uniform heat flux is imposed on the lower wall of the solid region. The investigation has been carried out at Reynolds numbers of 50, 75 and 100, for a nanofluid with 2% volume fraction. The nanoparticle diameters varied from 10 to 50 nm and variable Hartmann numbers ranging from 0 to 30 were considered. The results showed that in the case of ignoring viscous dissipations, using a magnetic field in conjugate heat transfer does not have a significant negative effect on the average Nusselt number, and despite the usual expectation, can increase the Nusselt number, especially at higher Reynolds numbers. It is also noted that the average Nusselt number when ignoring the viscous dissipations, is higher than when these dissipations are taken into account. Hence, the highest Nusselt number in this case, is observed at Reynolds and Hartmann number values of 100 and 30, respectively.