Unveiling the magic of localized magnetic field on vortex dynamics and heat transfer of tetra-hybrid nanofluid in lid-driven cavity: an insightful investigation

This paper investigates the effects of confined magnetic fields on the flow and thermal properties of nanofluids using the alternating direction implicit approach. The dimensionless version of the partial differential equation is computed by using the stream-vorticity formulation. Unlike most earlier investigations, we do not make the more reasonable assumption of a uniform magnetic field across the flow domain. However, we set up several localized magnetic fields in the shape of horizontal and vertical strips. We use a single-phase model to simulate the nanofluids and visualize the flow patterns around the magnetic strips in the flow regime. The present findings are validated by comparing them with the available results in the literature and finding a good agreement. We discover that without Laurent force, two main vortices dominate the flow near the horizontal walls of the cavity. The Lorentz force creates parallel vortices near vertical walls, while the Reynolds number enhances the magnetic field effect and heat transfer rate. Magnetic field disrupts smooth temperature distribution and mixes fluid layer faster. Nanoparticles affect skin friction more than the Nusselt number. SWCNT has higher thermal conductivity and lower viscosity, so it affects skin friction less and increases Nusselt number more than other nanoparticles (silver, titanium dioxide, copper). Silver and titanium dioxide exhibit higher density and specific heat, resulting in a more pronounced reduction in skin friction compared to other nanomaterials.