Heat transfer in hydrophobic microchannels: lattice Boltzmann analysis of partial magnetic field effects on non-Newtonian fluid dynamics

Numerical investigation of heat transfer (HT) enhancement and fluid flow characteristics in hydrophobic microchannels under a partial magnetic field influence is conducted using the lattice Boltzmann method (LBM), with particular focus on non-Newtonian fluid behavior. This study contributes significantly to the understanding of magnetohydrodynamic (MHD) phenomena in microchannel systems. The findings have direct applications in thermal management solutions for microelectronics cooling and biomedical microfluidic devices. Key findings reveal that strategic placement of magnetic fields in upstream regions can boost HT performance by 20% at Hartmann number [Formula: see text]. However, higher Hartmann numbers [Formula: see text] lead to increased flow resistance, especially in Newtonian fluids. The analysis demonstrates that shear-thinning fluids (power-law index [Formula: see text]) maintain more stable flow patterns with reduced magnetic field sensitivity, resulting in lower frictional losses compared to Newtonian counterparts. These results highlight the critical need for coordinated optimization of magnetic field configuration and fluid rheological properties to achieve optimal thermal performance while minimizing hydraulic resistance. The study concludes with recommendations for future work, including the investigation of adaptive magnetic field systems and the development of tailored non-Newtonian fluid formulations to further enhance microchannel system performance.