A numerical study of the natural convection of the laminar heat transfers in the stationary state was developed in a horizontal ring and compared between a heated trapezoidal internal cylinder and a cold elliptical outer cylinder. This annular space is traversed by a Newtonian and incompressible fluid. The Prandtl number is set to 0.7 (air case) for different Rayleigh numbers. The system of equ...

The purpose of this study is to investigate the effect of magnetic field on the fluid flow and natural convection of CuO-water nanofluids with variable properties in an inclined square enclosure. The horizontal walls of cavity are insulated, the left sidewall assumed as hot wall and the right sidewall assumed as cold wall. Effects of Rayleigh numbers 103, 104, 105</su...

Entropy generation of double diffusive natural convection in a three dimensional differentially heated enclosure has been performed numerically. Vertical walls of enclosure are heated differentially and remaining walls are adiabatic. The obtained results were presented via iso-concentration, iso-temperatures, velocity vector projection, particle trajectories, velocity profiles, iso-entropy, loc...

In this paper a transient free convection flow around a sphere with variable surface temperature and embedded in a porous medium has been considered. The temperature of the sphere is suddenly raised and subsequently maintained at values that varies with position on surface. The method of asymptotic expansions is applied for small Rayleigh numbers and then a finite-difference scheme is used to s...

Transient natural convection is numerically investigated in an enclosure using variable thermal conductivity, viscosity, and the thermal expansion coefficient of Al2O3-water nanofluid. The study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ ϕ ≤ 7%), the enclosure aspect ratio (AR =1), and temperature differences between the cold a...

The natural convection in differentially heated rectangular cavities with a fin attached to the cold wall was investigated numerically. The top and the bottom horizontal walls of the cavities were insulated while their left and the right vertical walls were maintained at a constant temperature Th and Tc, respectively with Th > Tc. The governing equations written in terms of the primitive variab...

An experimental and numerical study of free convection heat transfer from a channel consisting of a vertical sinusoidal wavy surface and a vertical flat plate has been carried out. The vertical wavy surface was maintained at a constant temperature, while the flat plate is adiabatic. A Mach-Zehnder Interferometer was used to determine the local heat transfer coefficients of sinusoidal wavy surfa...