The problem of natural convection in an inclined L-shaped enclosure filled with Cu/water nanofluid that operates under differentially heated walls in the presence of an inclined magnetic field is presented in this paper. The fully implicit finite difference method is used to solve the governing equations. A comparison with previously published results in special case of the present study is performed and a very good agreement is found. Heat transfer and fluid flow are examined for parameters of the Hartmann number (0 ≤ Ha ≤ 100), the nanoparticles volume fraction (0% ≤ ϕ ≤ 20%), the cavity inclination angle (0° ≤ ϑ ≤ 300°), the magnetic field inclination angle (0° ≤ γ ≤ 270°), the cavity aspect ratio (0.25 ≤ AR ≤ 0.6) and the Rayleigh number (103 ≤ Ra ≤ 106). It is found that, the presence of the magnetic field in the fluid region causes a significant reduction in the fluid flow and heat transfer characteristics. Also, a good enhancement in the heat transfer rate can be obtained by adding the copper nanoparticles to the base fluid.

This paper discusses the phenomenon of natural convection flow in an inclined, partially open enclosure filled with Al2O3–water nanofluid. In the cavity, the horizontal walls and the closed portions of the right wall are thermally insulated. Three thermal cases were considered for the left wall; in the first case, the left wall was considered to be uniformly heated; in the second case, a heat source was attached to the left wall; and in the third, the left wall had a heat sink. For case 2, there is a heat source attached to the left wall. For case 3, the left wall contains a heat sink. The partial differential equations governing the problem were solved numerically using the finite difference method. The obtained results were presented by the local Nusselt number, the average Nusselt number, streamlines, and isotherms with various pertinent parameters, namely, the Rayleigh number (103≤Ra≤106), the solid volume fraction (0≤ϕ≤0.2), different lengths of the heat source/sink (0.2≤BL≤1), different locations of the heat source/sink (0.2≤bL≤0.8), different lengths of the aperture (0.2≤BR≤1.0), different locations of the aperture (0.2≤bR≤0.8), and an inclination angle (0  deg≤ϑ≤π). It is found that, for all cases, the fluid features were strongly affected by changing the aperture length or the aperture location. Also, a clear increase in the mean Nusselt number could be obtained by increasing the Rayleigh number.Moreover, an enhancement in the average Nusselt number was found by increasing the nanoparticle volume fraction. A good natural convection could be obtained by increasing the heat source/sink length. Title the cavity by 60 deg leads to increase the absolute values of the stream function and a decrease in the maximum values of the maximum temperature. The best location of the heat source was found to be at the top of the left wall, whereas the best position of the aperture was found to be at the top of the right wall.

Read More: http://arc.aiaa.org/doi/abs/10.2514/1.T4408

In this article, the unsteady stagnation
point flow and heat transfer of a
nanofluid over a stretching sheet with the effects of magnetic field and porous
media is investigated numerically. The
effects of thermal radiation are also
considered. In contrast to the conventional no-slip condition at the surface,
Navier’s slip condition has been applied. The behaviour of the nanofluid was
investigated for three different nanoparticles in the water-base fluid, namely,
copper, alumina, and titanium. The simila
rity solution is used to reduce the
governing system of partial differential equations to a set of nonlinear ordinary
differential equations, which are then solved numerically by using the fourth-
order Runge-Kutta method along with shooting technique. The results
corresponding to the dimensionless velocity and temperature profiles, also the
skin friction and the reduced Nusselt
number are displayed graphically for
various pertinent parameters.