Numerical Investigation of Mixed Convection and Entropy Generation in a Wavy-Walled Cavity Filled with Nanofluid and Involving a Rotating Cylinder

This numerical study considers the mixed convection and the inherent entropy generated in Al [Formula: see text] O [Formula: see text] –water nanofluid filling a cavity containing a rotating conductive cylinder. The vertical walls of the cavity are wavy and are cooled isothermally. The horizontal walls are thermally insulated, except for a heat source segment located at the bottom wall. The dimensionless governing equations subject to the selected boundary conditions are solved numerically using the Galerkin finite-element method. The study is accomplished by inspecting different ranges of the physical and geometrical parameters, namely, the Rayleigh number ([Formula: see text]), angular rotational velocity ([Formula: see text]), number of undulations ([Formula: see text]), volume fraction of Al [Formula: see text] O [Formula: see text] nanoparticles ([Formula: see text]), and the length of the heat source [Formula: see text]. The results show that the rotation of the cylinder boosts the rate of heat exchange when the Rayleigh number is less than [Formula: see text]. The number of undulations affects the average Nusselt number for a still cylinder. The rate of heat exchange increases with the volume fraction of the Al [Formula: see text] O [Formula: see text] nanoparticles and the length of the heater segment.