Go to  Advanced Search

An analytical investigation of forced convective heat transfer to supercritical carbon dioxide flowing in a circular duct

Show full item record

Files in this item

Files Size Format Description   View
UBC_1977_A1 M34.pdf 9.091Mb Adobe Portable Document Format   View/Open
Title: An analytical investigation of forced convective heat transfer to supercritical carbon dioxide flowing in a circular duct
Author: Malhotra, Ashok
Degree: Doctor of Philosophy - PhD
Program: Mechanical Engineering
Copyright Date: 1977
Subject Keywords Carbon dioxide -- Thermal properties;Heat -- Convection
Issue Date: 2010-02-19
Series/Report no. UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/]
Abstract: A physical model and a numerical solution procedure has been developed to predict heat transfer behaviour in supercritical fluids. A major area of concentration was the modelling of the turbulent components of shear stress and heat flux. Traditionally, the turbulent fluxes are modelled by algebraic expressions such as the familiar mixing length methods. However, the use of this technique has not been entirely satisfactory. Newer methods for constant-property flows which model turbulent fluxes by considering the transport of quantities such as turbulent kinetic energy and the dissipation rate of turbulence have been extended to supercritical fluids. This involves the solution of two additional partial differential equations that are solved simultaneously with the equations of continuity, energy, and momentum. The numerical scheme has been developed on a completely two-dimensional basis by extending the Pletcher-DuFort-Frankel finite difference method. Computed results for velocity and temperature profiles as well as wall temperature distributions exhibited reasonable agreement with previous experimental data and therefore indicate the viability of the present method. Computations were carried out for supercritical carbon dioxide flowing through a circular duct in the reduced pressure range 1.0037 to 1.098. A consideration of the influence of buoyancy on the mean momentum balance permitted the calculation of unusual velocity profiles in this investigation. The existance of such velocity profiles had been accepted previously but the nature of their growth along a pipe has probably not been suggested previous to this work. No attempt was made to include buoyancy generated turbulence or additional fluctuating property correlations in this work, but suggestions are made regarding possible avenues of approach. Some of the incidental outcomes of this work were a new continuous universal velocity profile implicit in cross stream distance an a new mixing length distribution for turbulent pipe flows.
Affiliation: Applied Science, Faculty of
URI: http://hdl.handle.net/2429/20530
Scholarly Level: Graduate

This item appears in the following Collection(s)

Show full item record

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893