In the present study, heat transfer and entropy analysis for flow through a pipe system is considered. The Reynolds number and the pipe wall temperature effects on entropy distribution and total entropy generation in the pipe are investigated. Numerical scheme employing a control volume approach is introduced when solving the governing equations. Steel is selected as pipe material, while water ...

A numerical method based on the SIMPLE algorithm has been developed for the analysis of vapor flow in a concentric annular heat pipe. The steady-state response of a concentric annular heat pipe to various heat fluxes in the evaporator and condenser sections are studied. The fluid flow and heat transfer in the annular vapor space are simulated using Navier-Stokes equations. The governing equatio...

The Navier-Stokes equations are solved exactly, assuming the Navier slip boundary condition, for flow between coaxial circular cylinders (with possibly different slip lengths at the inner and outer walls), and flow in an equilateral triangular pipe. The velocity fields and total flow rates are found analytically. A relatively small slip length can lead to a large increase in the total rate of f...

Velocity fields for Poiseuille flow through tubes having general cross section are calculated using a path integral method involving the first-passage times of random walks in the interior of the cross sectional domain B of the pipe. This method is applied to a number of examples where exact results are available and to more complicated geometries of practical interest. These examples include a...

The influence of the inlet swirl velocity profile shape on the decay of swirl in steady-state, incompressible, laminar pipe flows is investigated by means of computational fluid dynamics. The investigation is carried out for a Reynolds number of 2000, which marks the upper limit of the laminar flow behavior for unidirectional pipe flow. Computations are performed for two different mean swirl nu...

Gas-lift pumps are devices for lifting liquid phase incorporating the gas phase to be injected in the bottom of liquid column. They are widely used in various industrial applications such as oil extracting in petroleum industries. Gas-liquid flow being the main part of the flow through these systems, flowing in vertical pipes of gas-lift pumps has different regimes namely bubbly, slug, chur...