Comparative analysis of Fe3O4/CoFe2O4 and NiZnFe2O4/ MnZnFe2O4 hybrid ferro-nanofluids flow under magnetic dipole effect over a slip stretching sheet

Abstract

The available external manipulation of ferrofluids through magnetic fields leads to applications in magnetically controlled actuation and drug targeting. This study investigates the behavior of magnetic hybrid ferro-nanofluids flowing over a stretched sheet with the inclusion of velocity slip and a magnetic dipole. The thermal characteristic of two different hybrid ferro-nanofluids, which are ferrite-cobalt ferrite (Fe3O4/CoFe2O4) and nickel zinc ferrite-manganese zinc ferrite (NiZnFe2O4/MnZnFe2O4) dispersed into a water-ethylene glycol, are theoretically analyzed and compared. The governing equations are developed using the Tiwari and Das model. The simplified equations are solved using the Keller box method. Results show that increased ferrohydrodynamic interaction and slip velocity contribute to higher velocity profiles. A stronger magnetic field intensity, by increasing the distance of the magnetic dipole, significantly improves the velocity profile but leads to a rapid decline in the temperature field. It is found that as the dimensionless distance increases, the temperature profile drops 0.15 % from Fe3O4/CoFe2O4 to NiZnFe2O4/MnZnFe2O4. There is an immediate 0.45 % drop in the velocity profile for Fe3O4/CoFe2O4 as velocity slip enhances, compared to NiZnFe2O4/MnZnFe2O4. The thermal field rises by 1.93 % as the magnetic field distance approaches the plate, influenced by the hybrid nanoparticles' volume fraction.