Heat transfer and entropy generation of ferro-water nanofluid over a Flat Plate in a Magnetic Field

This study numerically investigates the heat transfer characteristics and entropy generation of a ferro-water nanofluid flowing over a flat plate under the influence of an external magnetic field, employing the finite difference method. The impacts of varying the magnetic parameter (M, from 0 to 15) and the nanoparticle volume fraction (ϕ, from 0 to 0.1) are systematically analyzed. Results demonstrate that both increasing M and ϕ significantly enhance the local heat transfer coefficient. This enhancement is attributed to thermal boundary layer compression, with a magnetic field of M=10 reducing its thickness by approximately 33% compared to M=0. The analysis of entropy generation reveals that viscous and thermal irreversibilities are concentrated at the plate's leading edge, whereas magnetic irreversibility peaks in high-velocity zones. Notably, the average total entropy generation increases with both M and ϕ. At ϕ=0.05, it rose from approximately 1180W/m3−K (M=0) to 1600W/m3−K (M=15). The findings highlight a critical trade-off between achieving superior heat transfer rates and incurring greater thermodynamic irreversibilities in such systems.