Magnetohydrodynamics Flow of Hybrid Nanofluid Rotating in Annulus Through Two Coaxial Cylinders

A numerical investigation is conducted to examine the flow characteristics of the hybrid nanofluid rotating through an annulus formed within a coaxial cylinder. The study compares the heat performance of the hybrid nanofluid [composed of graphene oxide (GO), copper (Cu), and kerosene oil] with the base fluid (kerosene) and a nanofluid consisting of copper and kerosene oil. The inner wall of the coaxial cylinder remained stationary, while the outer wall underwent rotation. Additionally, a radial magnetic field was applied to examine its impact on flow and heat transfer characteristics. This study explores two scenarios: one where all walls are electrically insulating and another where the outer and inner walls are electrically conducting. The mathematical model, formulated as partial differential equations, was solved using the finite volume method. Graphical representations were used to analyze azimuthal velocity, temperature, Nusselt number, and skin friction under increasing magnetic intensity. The results indicated that a higher magnetic Hartmann number led to an increase in the distribution of temperature and azimuthal velocity in the middle of the annulus. Additionally, a higher magnetic field leads to an increase in the Nusselt number, which is more advantageous for the hybrid nanofluid than for Cu/kerosene oil. Electromagnetic damping is more evident in heat transfer when the inner/outer walls are electrically conducting than when all walls are insulated, as highlighted by the findings.