Natural convection in an annulus with a discrete heat source on the inner cylinder is studied numerically. The outer cylinder is isothermally cooled at a fixed low temperature, and the top wall, the bottom wall and unheated portions of the inner cylinder are thermally insulated. For low applied heat flux through the heater, as measured non-dimensionally by a Grashof number, Gr , the flow in the...

The gas delivered from a cylinder of Entonox (50% nitrous oxide and 50% oxygen) may not contain adequate quantities of oxygen if the cylinder has been cooled and then allowed to warm up in a vertical position.The composition of gas delivered from cylinders cooled to not lower than -40 degrees C. remains unaltered if the cylinders are rewarmed for 24 hours in a horizontal position at a temperatu...

Laminar free convection heat transfer from vertical and inclined arrays of horizontal isothermal cylinders in air was investigated experimentally and numerically. Experiments were carried out using Mach-Zehnder interferometer and the FLUENT code was used for numerical study. Investigation was performed for vertical and horizontal cylinder spacing from 2 to 5 and 0 to 2 cylinder diameters respec...

laminar free convection heat transfer from vertical and inclined arrays of horizontal isothermal cylinders in air was investigated experimentally and numerically. experiments were carried out using mach-zehnder interferometer and the fluent code was used for numerical study. investigation was performed for vertical and horizontal cylinder spacing from 2 to 5 and 0 to 2 cylinder diameters respec...

the gravity method is one of the first geophysical techniques used in oil and gas exploration. an algorithm is developed for a fast quantitative interpretation of gravity data generated by geometrically simple but also the estimated depths and other model parameters of a buried structure. following abdelrahman et al (1989). the general gravity anomaly expression produced by a sphere, an infinit...

We study the sinking of a dense cylinder initially supported horizontally at an air-water interface and then released. The sinking motion is studied experimentally and agrees quantitatively with a simple hydrodynamic model of the process. In particular, our model predicts that the time taken for the cylinder to become immersed in the liquid should be tsink approximately theta((lc/g)1/2), where ...

Abstract A numerical study of a two-dimensional laminar flow and heat transfer characteristics in horizontal channel containing two in-line obstacles different shapes, namely an upstream triangular cylinder downstream square cylinder, was carried out. It is based on coupling between the Lattice Boltzmann Method (LBM) Finite Difference (FDM). The airflow (Pr = 0.71) assumed to be incompressible....

A numerical study has been carried out for slot air jet impingement cooling of horizontal concentric circular cylinders. The slot air jet is situated at the symmetry line of a horizontal cylinder along the gravity vector and impinges on the bottom of the outer cylinder which is designated as θ=0°. The outer cylinder is partially opened at the top with a width of W=30mm and is kept at constant t...