Research Article | OPEN ACCESS
Fully-developed Turbulent Pipe Flow Using a Zero-Equation Model
Khalid Alammar
Mechanical Engineering Department, King Saud University, Riyadh 11421, Kingdom of Saudi Arabia, P.O. Box 800, Tel.:+ 96614676650; Fax: + 96614676652
Research Journal of Applied Sciences, Engineering and Technology 2013 4:687-690
Received: September 13, 2012 | Accepted: October 19, 2012 | Published: June 20, 2013
Abstract
Aim of this study is to evaluate a zero-equation turbulence model. A fully-developed turbulent pipe flow was simulated. Uncertainty was approximated through grid-independence and model validation. Results for mean axial velocity, u+ and Reynolds stress had maximum error of 5%, while results for the friction factor had negligible error. The mean axial velocity was shown to increase and extend farther in the outer layer with increasing Reynolds number, up to 106. There was no effect of Reynolds number on u+ below wall distance, Y+, of 100. Similar to the friction velocity, peak of the Reynolds stress was shown to increase and extend farther in the outer layer with increasing Reynolds number. There was no effect of Reynolds number on Reynolds stress below wall distance of 20. The new turbulence model is equally applicable to developing and external flows using the same constant. For wall-bounded flows, the constant is a function of wall roughness.
Keywords:
Reynolds stress, skin friction, turbulence modeling,
Competing interests
The authors have no competing interests.
Open Access Policy
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Copyright
The authors have no competing interests.
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ISSN (Online): 2040-7467
ISSN (Print): 2040-7459 |
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