Next Article in Journal
Phase Competitions behind the Giant Magnetic Entropy Variation: Gd5Si2Ge2 and Tb5Si2Ge2 Case Studies
Previous Article in Journal
Entropy vs. Majorization: What Determines Complexity?
Entropy 2014, 16(7), 3808-3812; doi:10.3390/e16073808
Letter

Entropy Generation in Steady Laminar Boundary Layers with Pressure Gradients

1,2,*  and 3
1 Mechanical Engineering Department, University of Idaho, Idaho Falls, ID 83402, USA 2 Institut für Kernenergetik und Energiesysteme (IKE), Universität Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germany 3 Osney Thermo-fluids Laboratory, Department of Engineering Science, University of Oxford, Osney Mead, Oxford OX2 0ES, UK
* Author to whom correspondence should be addressed.
Received: 16 April 2014 / Revised: 3 July 2014 / Accepted: 7 July 2014 / Published: 10 July 2014
View Full-Text   |   Download PDF [697 KB, 24 February 2015; original version 24 February 2015]   |   Browse Figure

Abstract

In an earlier paper in Entropy [1] we hypothesized that the entropy generation rate is the driving force for boundary layer transition from laminar to turbulent flow. Subsequently, with our colleagues we have examined the prediction of entropy generation during such transitions [2,3]. We found that reasonable predictions for engineering purposes could be obtained for flows with negligible streamwise pressure gradients by adapting the linear combination model of Emmons [4]. A question then arises—will the Emmons approach be useful for boundary layer transition with significant streamwise pressure gradients as by Nolan and Zaki [5]. In our implementation the intermittency is calculated by comparison to skin friction correlations for laminar and turbulent boundary layers and is then applied with comparable correlations for the energy dissipation coefficient (i.e., non-dimensional integral entropy generation rate). In the case of negligible pressure gradients the Blasius theory provides the necessary laminar correlations.
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Share & Cite This Article

Further Mendeley | CiteULike
Export to BibTeX |
EndNote
MDPI and ACS Style

McEligot, D.M.; Walsh, E.J. Entropy Generation in Steady Laminar Boundary Layers with Pressure Gradients. Entropy 2014, 16, 3808-3812.

View more citation formats

Related Articles

Article Metrics

For more information on the journal, click here

Comments

Cited By

[Return to top]
Entropy EISSN 1099-4300 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert