Natural convection of MHD hybrid nanofluid (Fe3O4-MWCNT) in annular cavity fitted with fins: numerical approach

In this paper, we study numerically the natural convection of MHD hybrid nanofluid (Fe3O4-MWCNT) in annular cavity fitted with fins under magnetic fields. The inner cylinder is subjected to volumetric heat generation while the outer cylinder is kept adiabatic. The governing equations of mass, momentum and energy equation for both the fluid and the solid are solved by the finite volume method, using the commercially available CFD software Fluent 6.3.26. The fluid is a water-based hybrid nanofluid containing various nanoparticle combinations of Fe3O4 with MWCNT. The effect of the magnetic field is carried out and investigated for different Hartmann number Ha, for a cavity without fins N=0 and with fins N=8. Results are presented by magnetic field and temperature contours as well as velocity profiles in the gap of the cavity with and without fins. The results indicate that, Increasing Ha suppresses convective currents, leading to stratified temperature profiles and a transition towards conduction-dominated heat transfer. The addition of fins reduces fluid temperature and enhances heat transfer within the cavity