We investigate the nature of entropy generation for natural convection in a twodimensional square section enclosure vibrating sinusoidally perpendicular to the applied temperature gradient in a zero-gravity field. The enclosure is assumed to fill with porous media. The Darcy momentum equation is used to model the porous media. The full governing differential equations are simplified with the Bo...

Steady state natural convection is numerically investigated in an enclosure using variable thermal conductivity, viscosity and thermal expansion coefficient of Al2O3–water nanofluid. This study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ Φ ≤ 7%), enclosure aspect ratios (0.5 ≤ AR ≤ 2) and temperature differences between the cold...

A combined numerical and experimental study is reported of solid/liquid phase change in porous media with natural convection in the melt region. The model is based on volume averaged transport equations, while phase change is assumed to occur over a small temperature range. Experiments are performed in a vertical, square enclosure using gallium and glass beads as the fluid and the porous matrix...

Natural convection in a square enclosure having two wavy vertical walls is studied. An enclosure is filled with fluid-saturated porous media. A cavity is heated spatially on bottom wall while remaining walls are maintained at lower temperature. The objective of this study is to examine the flow field, temperature distribution and heat transfer inside the cavity when values of Darcy number, Rayl...

The entropy generation during transient laminar natural convection in a square enclosure is numerically investigated. Two different cases are considered. The enclosure is heated either completely or partially from the left side wall and cooled from the opposite side wall. The bottom and the top of the enclosure are assumed as insulated. The Boussinesq approximation is used in the natural convec...