Natural convection of ternary hybrid nanofluid flow in an inclined porous trapezoidal enclosure

This study reveals the flow and heat transfer of natural convection flow of a ternary hybrid nanofluid in an inclined trapezoidal cavity embedded in a porous medium. The left inclined wall of the enclosure is isothermally heated while the right inclined wall is cold. The top and bottom walls are adiabatic. Using variable transformations, the governing equations of the problem are transformed into a dimensionless system of equations. For numerical simulations, a coordinate transformation is utilized which converts the physical domain to computational domain. The equations of computational domain are solved using the finite difference method. The effects of volume fractions of nanoparticles (φ1, φ2, φ3), Rayleigh number (Ra), enclosure inclination (γ) and inclined walls' inclination (Ω) are elucidated with streamlines, isotherms and average Nusselt number. Intensity of stream function gradually increases with the increase of enclosure inclination, Rayleigh number, and nanoparticles' volume fractions. On the other hand, the average Nusselt number exponentially augments for increasing volume fractions of nanoparticles and Rayleigh number, however, it shows a parabolic pattern for an increase in the inclination angles of the enclosure and inclined walls. Moreover, Al2O3-water nanofluid's heat transfer is higher than pure water and Cu-Al2O3-water hybrid nanofluid's heat transfer is higher than that of the nanofluid. It is also found that the average Nusselt number for ternary hybrid nanofluid is higher than nanofluid's and hybrid nanofluid's average Nusselt number, although the total nanoparticles' volume fraction for ternary hybrid nanofluid is lower than for those.