The behavior of convective heat transfer in an enclosure filled with Cu–water nanofluid with a baffle has been numerically studied using the finite element method. The enclosure’s top and bottom walls were adiabatic, while the other two were maintained at various temperatures. The left hot wall had an effective thickness and a baffle was added to the bottom wall. The influence of different parameters like the nanoparticle’s concentration (ϕ), Rayleigh number (Ra), the thermal conductivity ratio of the thick wall (Kr), baffle angle (Ø), and the hot wall thickness (D) on the isotherm and fluid flow patterns were examined. The result showed that the average Nusselt number was enhanced, owing to the strength of the buoyancy force becoming more effective. Furthermore, as the baffle inclination angle increased, the maximum stream function at the core corresponded to the angle when it reached Ø=60°, then it gradually decreased to the minimum value as the baffle angle reached close to Ø=120°.

The proper process of applying heat to many technological devices is a significant challenge. There are many nanofluids of different sizes used inside the system. The current study combines this potential to improve convection effects, considering numerical simulations of natural convection using Cu/water nanofluids in a square enclosure with bottom blocks embedded in baffles. The enclosure consists of two vertical walls with isothermal boundary conditions; the left wall is the sinusoidal heat source, whereas the right wall is cooled. The investigations dealt with the influences of nanoparticle concentration, Rayleigh number, baffle length, and thermal conductivity ratioon isotherms, stream functions, and average Nusselt number. The results present that, when the Rayleigh number rises, the fluid flow velocity increases, and the heat transfer improves. Furthermore, the baffle length case (Lb = 0.3) provides higher heat transfer characteristics than other baffle height cases.