Magnetic field effect on mixed convection in ferrofluid filled c-shaped cavity with rotating circular cylinder at different positions with intruded heated sides

Mixed convection heat transfer using nanofluids is gaining more attraction among engineers for its wide uses. Ferrofluids are magnetic nanofluid that contains nanoscale iron compounds in a base fluid. In this study, finite element simulations have been performed in a C shaped cavity, filled with ferrofluid (Fe3O4 − water). Intruded walls of C are heated, a side wall and rotating cylinder working in lower temperature. The effect on fluid flow, Nusselt number have been investigated with varying volume fraction (φ=0 to 0.20), Hartmann number (0 to 40), and rotation of cylinder. For three different geometries with different position of circular cylinders centered at (0.2, 0.1); (0.45, 0.1); (0.85, 0.1) have been investigated numerically. Geometry with cylinder at (0.85, 0.1) showed maximum performance in heat transfer. But increasing angular velocity of cylinder does not contribute core fluid movement in this position, and has less performance for cooling intruded upper wall. Increasing magnetic field causes reduction of flow strength and heat transfer decreases. Heat transfer increases for increased flow strength (increased rotation of cylinder) and for increased solid volume fraction.