Temperature Reduction of a Hot Component Enclosed in a Ring Filled with Power-Law Ferrofluid Under the Effect of Magnetic Field and Heat Absorption: Benefit from LBM Ability to Simulate Radiation–Convection Heat Transfer

The failure to consider thermal radiation in addition to free convection heat transfer in many cases such as heat exchangers will cause an unavoidable error in the flow analysis. Due to the complexity of volumetric radiation modeling in solving various problems, it is difficult to simulate this issue, especially through computer coding. The reason for this numerical study is the lack of extensive investigation of the effect of volumetric radiation on non-Newtonian nanofluid flow under magnetic field and heat absorption. By using the LBM and simulating the natural convection phenomenon, the cooling of a square-shaped component within a sector of a ring containing a non-Newtonian nanofluid has been modeled in the present research. The findings indicate that the presence of radiation increases the average value of the Nusselt number for the shear thickening, the Newtonian, and the shear thinning fluids by about 17%, 11%, and 8.5%, respectively. The growth of the thermal performance index and the mean Nusselt Number value is observed via the enhancement of the fluid power-law index, especially in the absence of heat absorption. In most cases, the presence of nanoparticles improves the heat transfer rate, especially in cases where thermal conduction dominates convection. There is the lowest cooling performance index and magnetic field effect for the cavity placed at the angle of 45°. By designing the system in such a way that the magnetic field is imposed on the system at different angles and positions, the thermal performance can be improved to a great extent.