Investigation of the optimum design of magnetic field arrangement to enhance heat transfer performance of Fe3O4-water magnetic nanofluid

In this study, numerical simulations were conducted to explore the best possible magnetic field arrangement that can maximize the heat exchange performance of Fe3O4-water magnetic nanofluid. Orientation of magnets poles, number of magnets, and the distribution of magnetic field intensity over the flow path are studied to obtain the optimum design which is then tested at various values of magnetic nanoparticles volume fraction, magnetic flux density, and Reynolds number. Results indicated that the optimum design is achieved by placing magnets with N-N orientation and adjusting the magnetic flux density to increase by a rate of 100% between each two suc-cessive magnets along the path of the flow. Results also revealed that the average Nusselt number and pressure drop increase when the magnetic flux density is increased. Furthermore, it was found that the effect of increasing magnetic nanoparticles volume fraction on the heat transfer performance is higher at low Reynolds number. An increase of the average Nusselt number in the range of 16.44%-24.46% compared to the design without mag-netic field was achieved when using the optimum design with an average magnetic flux density of 1000 Gauss, and magnetic nanoparticles volume fraction of 4%.

Automated summary

Numerical simulations were conducted to find the best magnetic field arrangement for maximizing heat exchange performance of Fe3O4-water magnetic nanofluid. The orientation, number, and distribution of magnetic field were studied, and the optimum design was tested under different conditions. Results showed that placing N-N oriented magnets and increasing magnetic flux density between magnets achieved the best design. Increasing magnetic flux density resulted in higher average Nusselt number and pressure drop. The effect of increasing magnetic nanoparticles volume fraction was more significant at low Reynolds number. The optimum design with an average magnetic flux density of 1000 Gauss and magnetic nanoparticles volume fraction of 4% achieved a 16.44%-24.46% increase in average Nusselt number compared to the design without magnetic field.