Heat Transfer and Entropy Generation Minimization in a Lid-Driven Enclosure Filled with Nanofluid

This study presents an examination of mixed convection flow within a lid-driven square enclosure containing two cylinders, filled with Al 2 O 3 -water nanofluid. The finite volume method was employed, utilizing the Ansys-Fluent 14.5 software tool, to resolve the proposed mathematical model. The research was primarily centered on evaluating the impact of varying parameters such as the solid volume fraction (ϕ), Reynolds numbers (Re), and cylinder diameter (D) on heat transfer characteristics and entropy generation (St). As Re was increased, an enhancement in heat transfer was observed, accompanied by a reduction in St and Bejan number (Be). Augmenting ϕ resulted in increased heat transfer and Be, yet decreased St. A surge in D corresponded with elevated St and diminished Be. The investigation indicates that a cylinder diameter of D=0.1H optimizes convective heat exchange and minimizes St, with the average Nusselt number 𝑁𝑢̅̅̅̅ consistently decreasing as D escalates. These findings hold substantial potential for the optimization of thermal systems.