Investigating the Sensitivity of Tetra-hybrid Microfluidic Flow Under Magnetic Field Localization

This study explores the sensitivity of tetra-hybrid microfluidic flow to localized magnetic fields, focusing on their impact on flow dynamics, stress distribution, and thermal behavior. A rectangular cavity (aspect ratio 4:1) filled with a tetra-hybrid nanofluid is analyzed, with the top and bottom walls moving in the same direction. A confined magnetic field, structured in horizontal and vertical strips, is introduced to assess its influence. An alternating-direction implicit method has been used to enhance numerical stability and efficiently solve the discretized governing equations, and the single-phase model has been used to model the fluid. Furthermore, custom MATLAB codes, employing the Stream-Vorticity formulation and a finite difference method, are used to solve the governing equations. The findings demonstrate that in-creasing the magnetic field strength up to 500 enhances heat transfer by 65%. Among nanostructures, a 20% silver concentration yields the highest improvement, increasing the Nusselt number by 313%, fol-lowed by SWCNT (54%), TiO₂ (43%), and Cu (31%). Regarding skin friction, silver and TiO₂ reduce it by 65%, while Cu lowers it by 52%. However, SWCNT exhibits an opposite effect, increasing skin friction by 138% due to its elongated structure, which enhances flow resistance. These findings highlight the poten-tial for controlled magnetic field applications to optimize nanofluid performance in advanced thermal and biomedical systems.