Effect of Magnetic Field on Heat Transfer Enhancement Using Fe3O4 Nanofluids In A Heated Pipe

The effects of various magnetic field intensity on heat transfer enhancement, hence an increase in Nusselt number (Nu), in a horizontal pipe heated with constant heating flux of 420W for different turbulent flow rates Fe3O4/water nanofluids were experimentally investigated. Fe3O4/water nanofluids of different volume concentrations of 1.2, 0.6, 0.3 vol.% will be used as the test fluid. Experiments were conducted for Reynolds number range of 2180<Re<9160 and for three different magnetic field intensity 15.1, 30.3, 45.5 mT. Initial results using Fe3O4/water nanofluid of 1.2 vol.% showed that Nu increases in the presence and absence of a magnetic field compared with water. Also, Nu increases with higher values of Re for aforementioned nanoofluid concentration and water. However, in the absence of a magnetic field, the average increase in Nu for Fe3O4-nanofluids was 16.7% relative to water, while, the average increase in Nu was 8.8%, 13.1%, and 23.9% under the application of magnetic field intensity of 15.1, 30.3, 45.5 mT relative to the absence of magnetic field, respectively. Based on that, it can be concluded that in the presence of magnetic field using Fe3O4-nanofluids, higher values of Nu is achieved and consequently an increase in heat transfer rate. These preliminary results can be useful for enhancing heat transfer in many engineering applications such as heat exchangers and electronic devices.