Author

Lei Liu

Publication Date

1994

Document Type

Dissertation/Thesis

First Advisor

Payvar, Parviz

Degree Name

M.S. (Master of Science)

Department

Department of Mechanical Engineering

LCSH

Non-Newtonian fluids||Laminar flow

Abstract

Laminar flows of Newtonian and non-Newtonian fluids through rectangular ducts are numerically investigated in this thesis. The objective of this thesis is to find a suitable constitutive equation that can effectively model viscoelastic fluids. Constitutive equations represent the rheological behavior of a fluid. In order to describe the secondary flow and the heat transfer enhancement of laminar viscoelastic flow through non-circular ducts, the Criminale-Erickson-Fibley (CEF) constitutive equation, which takes the normal stress difference into account, is employed to model a broad category of fluids. Based on the CEF model, a set of simplified non-dimensional governing equations are derived, where power law is used for both apparent viscosity and the second normal stress coefficient. The numerical procedure for three-dimensional parabolic flow is employed, where the momentum equations in the cross-stream directions are solved by the SIMPLER algorithm given by Patankar. Numerical results for hydrodynamically developed flow, hydrodynamically developing flow, thermally developed flow as well as simultaneously developing flow are reported based on Newtonian, purely viscous and viscoelastic fluids. It is illustrated that the numerical results agree well with the available analytical solutions. It is also shown that the CEF model effectively describes the rheological phenomena of viscoelastic fluids.

Comments

Includes bibliographical references (pages [79]-80)

Extent

80 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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