Experimental study of the effect of position and intensity of a constant magnetic field on the forced convection heat transfer of Fe2O3 / water nanofluid in the developing thermal region

In this experimental study, the forced convection heat transfer of thermally developing Fe2O3/water nanoparticles inside a copper tube under magnetic field created by a number of permanent flat magnets is investigated. Experiments have been carried out under laminar flow regime and uniform heat flux boundary condition and the influence of magnetic field position and intensity. The objectives of this study were to investigate the effect of using Fe2O3/water nanofluid, flow Reynolds number, intensity and magnetic field position on the thermal behavior of the flow. Validation of the test apparatus was performed using distilled water and compared with the theoretical results, which eventually achieved good agreement. The results show that due to the influence of the magnetic field on the Fe2O3/water nanofluid, secondary flow and boundary layer deformation occur, the heat transfer changes and its variation is dependent on the flow profile and intensity and position of the magnetic field. Increasing the intensity of the magnetic field perpendicular to the flow at a single point in the constant Reynolds causes a sudden increase in the local convection heat transfer coefficient but the mean convection heat transfer coefficient in the latter case is higher than in the former case.