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Viscous flow through sudden contractions

Thesis (DTech (Chemical Engineering))--Cape Technikon, Cape Town, 2004 / Despite efforts since the 1950s, laminar flow through pipe fittings is still a topic that
needs investigation (Jacobs, 1993). Most experimental studies on this topic include
fittings such as contractions, expansions, elbows, valves and orifices (Edwards et aI.,
1985; Turian et al., 1998; Pal & Hwang, 1999). Although sudden contractions are
not often found in industry, most researchers included these fittings as part of their
experimental investigation.
The volume of work done on flow through sudden contractions over the last 50
years (e.g. Bogue, 1959; Christian et aI., 1972; Vrentas & Duda, 1973; Boger, 1987;
Bullen et aI., 1996; Sisavath et aI., 2002), establishes its place of importance in the
fundamental understanding offluid flow and fluid mechanics.
There are inconsistent reports on the status ofthe study ofNewtonian fluids flowing
through sudden contractions, i.e., that "it is a solved problem" (Boger, 1987) and
"that it is far from being resolved" (Sisavath et aI., 2002). One reason for this
apparent contradiction is the fact that most experimental studies do not agree with
one another or with analytical and numerical studies. A state-of-the-art literature
review by Pienaar et al. (2001) confirmed this and that further investigation of this
topic is required.
To explore these contradictions, it was necessary for one study to do both an
experimental and numerical investigation and compare the results with existing
literature. It was also important to find some basis for agreement of experimental
work and not just add another data set to the existing scattered database.
A test facility was built for testing three contraction ratios, i.e., ~ = 0.22, 0.50 and
0.85. A range ofNewtonian and non-Newtonian fluids was tested over a wide range
ofReynolds number (Re = 0.01 - 100 000).

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/929
Date January 2004
CreatorsPienaar, Veruscha
PublisherCape Technikon
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Rightshttp://creativecommons.org/licenses/by-nc-sa/3.0/za/

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