Nanofluid flow and heat transfer in a cavity with variable magnetic field.

Fe3O4-water nanofluid flow in a cavity with constant heat flux is investigated using a control volume based finite element method (CVFEM). Effects of Rayleigh and Hartmann numbers and volume fraction of Fe3O4 (nano-magnetite, an iron oxide) on flow and heat transfer characteristics are analyzed. Results indicate that the temperature gradient is an increasing function of the buoyancy force and the volume fraction of Fe3O4, but it is a decreasing function of the Lorentz force. Also, the rate of heat transfer is augmented with an increase in the Lorentz force. However, the opposite is true on the rate of heat transfer with the buoyancy force. Furthermore, the core vortex moves downward with an increase in the Lorentz force. It is expected that the results presented here will not only provide useful information for cooling of electronic components but also complement the existing literature.