Heat transfer enhancement in zigzagged enclosure with winged circular baffles filled with radiative SWCNT–water nanofluid

This work presents a numerical investigation of natural convection heat transfer in a zigzagged square enclosure fitted with circular baffles and filled with a radiative SWCNT-water nanofluid. The effects of baffle geometry, including radius and inter-distance, as well as the role of lateral wings, are analyzed to optimize the thermal performance of the system. The governing equations are solved using COMSOL Multiphysics based on the finite element method, incorporating magnetic field and thermal radiation effects. The results reveal that accounting for nanoparticle radiation enhances heat transfer by up to 40%, while enlarging the baffle radius from 0.05 to 0.1 increases convective exchange by 16.6%. In contrast, strengthening the magnetic field reduces heat transfer by approximately 34.4%. Furthermore, equipping the baffles with lateral wings improves heat transfer efficiency by 23.8% compared to the classic design. The study identifies an optimal baffle inter-distance of D= 0.4, which maximizes convective heat transfer. These findings provide useful design guidelines for improving the efficiency of nanofluid-based heat sinks.