Lattice Boltzmann simulation of natural convection in partially heated cavities utilizing kerosene / cobalt ferrofluid

In this paper, heat dissipation effect of a ferrofluid on natural convection flow in a partially heated cavity in the presence of an external magnetic field outside of the cavity has been analyzed with lattice Boltzmann method (LBM). The cavity is filled with kerosene as the carrier fluid and nanoscale ferromagnetic of cobalt. This study has been carried out for the pertinent parameters in the following ranges: the Rayleigh number of base fluid, Ra=103–105, the volumetric fraction of nanoscale ferromagnetic between 0 and 4%, the size of the nanoscale ferromagnetic is fixed at 45nm. As the size of the heater is equal to H/3, the center of the heater is investigated at Yp= 0.25H, 0.5H and 0.75H. Results show that the heat transfer decreases by the increase of the nanoscale ferromagnetic volume fraction for various Rayleigh numbers. The external magnetic field influences the nanoscale ferromagnetic at Ra=104 more than other Raleigh numbers as the least values are observed at Ra=103. While the heat transfer obtains the greatest value at Yp= 0.5H for multifarious Rayleigh numbers, the greatest effect of the nanoscale ferromagnetic for Ra=104 and 105 is perceived at Yp= 0.75H.