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

This study reveals the natural convective flow and heat transfer 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. A clear distinction from many other studies is that a coordinate transformation is utilized here that converts the physical domain to the computational domain. The equations of the computational domain are then solved using the finite difference method. The important findings show that the 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 that of 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 the nanofluid's and hybrid nanofluid's average Nusselt number, although the total nanoparticles' volume fraction for ternary hybrid nanofluid is lower than for those.