Heat transfer analysis of hydromagnetic hybrid nanofluid (H2O) containing Ag–TiO2 nanoparticles in a slanted triangular enclosure with heated fins

Abstract

Solar collectors are devices that transform solar irradiation energy into thermal energy for various purposes. Among different solar thermal collectors, solar dish collectors are remarkable for having the highest solar-to-thermal energy conversion efficiency. These collectors are available with various receiver shapes like external, cavity, spiral and volume receivers. Notably, cavity receivers, with their unique structure, exhibit superior efficiency compared to other receiver types. Recently, researchers have explored different shapes of cavity receivers, such as triangle, circular, square and hexagonal, to enhance thermal efficiency. In light of this, the present study investigates the heat transfer behavior occurring in an inclined permeable triangular enclosure with heated fins, using a (Ag–TiO2/H2O) hybrid nanofluid as the working fluid. The mathematical modeling of hybrid nanofluid flow within the triangular enclosure is accomplished using the Navier–Stokes equations under the Boussinesq approximation, and dimensionless governing equations are solved through an in-house MATLAB code integrated with a finite difference method. The findings indicate that enhancing the Rayleigh number, thermal radiation and magnetic field boosts the heat transfer rate for a nanoparticle volume fraction of 5%. A decrease in the Darcy number leads to a shift in the flow pattern, causing the vortex cell to relocate to the top left. Higher values of Rayleigh number and thermal radiation effects are associated with a superior average heat transfer rate. Comparatively, the average heat transfer rate is slightly greater in an inclined cavity with compared to an uninclined cavity. This emphasizes the focus of numerous studies on nanofluid flow in inclined square cavities, particularly in the context of solar energy.