Momentum slip-induced free convective thermal and mass transport in Cu-water nanofluid flow: Impact of nanoparticle triboelectrification and nanoparticle volume fraction

This study investigates free convective heat and mass transport in Cu-water nanofluid flow over a wall surface, with particular emphasis on the combined effects of momentum slip, nanoparticle triboelectrification, and nanoparticle volume fraction. The novelty of the study lies in incorporating nanoparticle triboelectrification, nanoparticle volume fraction and momentum slip simultaneously within a modified Buongiorno model, thereby providing a framework for examining their coupled effects on nanofluid transport. Unlike studies that mainly focus on externally imposed magnetohydrodynamic effects, the present model considers nanoparticle charging through triboelectric interactions and examines its influence on flow, heat transfer, and mass transport. The governing flow, energy, and nanoparticle concentration equations are transformed into a coupled system of similarity equations and solved numerically using MATLAB's bvp4c solver. The results show that momentum slip and nanoparticle triboelectrification significantly influence the transport characteristics. Increasing the momentum slip parameter from 1.0 to 5.0 enhances the heat transfer rate by 21.22%. Increasing the electrification parameter from 0.1 to 0.5 increases the heat transfer rate by 35.38%, the skin-friction coefficient by 92.55%, and the mass transfer rate by 48.11%. The results further demonstrate that nanoparticle triboelectrification strongly enhances both thermal and mass transport, while momentum slip primarily promotes heat transfer. Variations in nanoparticle volume fraction also modify mass transport near the surface. These findings demonstrate the importance of considering triboelectrification and momentum slip together when modeling nanofluid transport and can provide useful insights for the design of thermal management systems requiring enhanced heat and mass transfer.