Unsteady convective ferrohydrodynamic flow of MnZnFe2O4/FeCrNbB - EG hybrid nanofluid in a horizontal channel with porous fins and semi-circular heaters

In this study, we investigate the unsteady incompressible flow of ethylene-glycol (EG) based MnZnFe2O4/FeCrNbB hybrid nanofluid through a horizontal channel. Three semi-circular heaters are mounted on the lower channel wall, whereas four porous fins are mounted on the upper channel wall. The Forchheimer model is utilized to describe convective nanofluid flow within the porous fins. Also, a variable magnetic field is produced by an electrical wire within each heater and induces motion and heat transfer within the hybrid nanofluid. Governing equations associated with the mathematical model are numerically solved via the mixed finite element technique. Using the computed graphical and tabular results, we examine the effects of the magnetic parameter (10(5) <= Mn <= 3 x 10(6)), size of the porous fins (0.2 <= h(fin) <= 0.6), heater radius (0.2 <= r(0) <= 0.3), and solid volume fractions of MnZnFe2O4 and FeCrNbB nanoparticles (0 <= phi(1) <= 0.02 and 0 <= phi(2) <= 0.02) on the flow velocity, streamlines, isotherms, pressure drop, and heat transfer performance in the channel. The main findings of the study are that increasing the magnetic number and volume fractions of MnZnFe2O4 and FeCrNbB nanoparticles, and decreasing the height of the porous fins and size of the heaters, leads to greater convective heat transfer in the channel. Furthermore, the pressure drop is enhanced when each of the aforementioned parameters is increased.