Lattice Boltzmann simulation of MHD non-Newtonian power-law nanofluid in a rectangular enclosure using GPU computing

In this paper, a numerical study has been conducted on the heat transfer of non-Newtonian nanofluid (Copper-Water) in a vertical rectangular cavity in the presence of a horizontal or angular magnetic field. The numerical simulation has been accomplished using the graphics process unit (GPU) accelerated multiple-relaxation-time (MRT) lattice Boltzmann method. A modified power-law model has been employed to characterize the non-Newtonian fluid behavior. The simulation presented in this paper spans a range of power-law index (0.6 ≤ n ≤ 1.0), Hartmann number (0 ≤ Ha ≤ 50) and nanoparticle volume fraction (0 ≤ φ ≤ 0.05). Results indicate that an increment of the power-law index leads to reduce the heat transfer rate from the hot walls. The heat transfer rate also drops when the Hartmann number is incremented. Moreover, augmentation of the volume fraction of nanofluids can enhance the average Nusselt number. Finally, the average Nusselt number increases when the magnetic field is applied at a different angle instead of 0°.