On the free convective flow and heat transfer of Prandtl nanofluid in a microchannel

Prandtl nanofluids are increasingly vital in microfluidic devices and electronic cooling systems due to their enhanced heat transfer characteristics, yet their behavior in porous microchannels with internal heat generation remains unexplored. This study numerically investigates free convection heat and mass transfer of a non-Newtonian Prandtl nanofluid in a vertical porous microchannel, incorporating Brownian motion, thermophoresis, wall suction, and nonlinear internal heat generation. The governing equations are solved using the adaptive collocation-based bvp4c algorithm in MATLAB. Grid independence is achieved with a relative error of O (10 −10 ), yielding a skin friction coefficient of 0.244343857. Results show that increasing the magnetic field parameter suppresses velocity due to Lorentz damping while thickening the thermal boundary layer. The Nusselt number increases significantly with Prandtl number (from 17.71 at Pr = 5 to 34.84 at Pr = 12) and suction velocity (from 11.26 at V 0 = 0.2 to 20.13 at V 0 = 0.6). These quantitative findings provide benchmarks for optimizing microchannel thermal management systems.