Effects of parallel magnet bars and partially filled porous media on magneto-thermo-hydro-dynamic characteristics of pipe ferroconvection

•This study intended to address heat transfer enhancement for forced ferroconvection.•Influence of magnetic field would be significant specially in low Re number.•Synergy of porous media and magnetic field lead to heat transfer enhancement up to 2.2-fold.•With given geometry, the effect of porous media is much more than magnetic field.•Heat transfer enhancement results in decreasing insulation heat loss.•Transverse uniform magnetic field causes 3D vortices and confer laminar flow a mixing feature. In this experimental-numerical study, effects of transverse magnetic field of parallel magnet bars perpendicular to the fluid flow direction and partially filled porous media are investigated. Moreover, constant heat flux is applied on the outer surface of a circular straight horizontal pipe and concentric porous media is embedded inside it. Magnet bars are located right at the entrance of pipe and a thick layer of insulation is wrapped the pipe to prevent heat loss. In addition, a 3D numerical simulation is performed using CFD techniques to capture the influence of these two factors on the thermohydrodynamic behavior of ferrofluid flow. Hybrid scheme of finite volume method and SIMPLE algorithm are employed to discretize and solve governing equations as well as TDMA for solving the linear algebraic matrix equation. Mineral oil is used as a base fluid and ferrofluid with three different volume fractions 0.5, 1 and 2% are prepared for the experiment. Finally prepared experimental setup configuration in this investigation leads to this conclusion that in comparison with magnetic field, although porous media induce more unfavorable pressure loss, it will bring more heat transfer enhancement as well.