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Entry length effects for momentum, heat and mass transfer in circular ducts with laminar flow
Author(s) -
Hayes Robert E.,
DonosoBravo Andrés,
Mmbaga Joseph P.
Publication year - 2015
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22177
Subject(s) - nusselt number , laminar flow , mechanics , thermodynamics , heat flux , heat transfer , constant (computer programming) , heat transfer coefficient , materials science , chemistry , physics , reynolds number , turbulence , computer science , programming language
Abstract This paper shows the results of a computational study relating to the calculation of heat and mass transfer coefficients in the entry region of a circular duct. Laminar flow with temperature dependent physical properties is used. The results are compared with the classical results obtained for a fluid with constant physical properties. It is seen that a plot of the Nusselt number versus the inverse Graetz number does not yield a unique curve, but rather depends on the channel diameter, wall temperature or flux value, and the inlet fluid velocity. The deviation from the curve obtained with constant physical properties increases as the velocity decreases.