Drag with external and pressure drop with internal flows : a new and unifying look at losses in the flow field based on the second law of thermodynamics

Publikationstyp
Journal Article
Date Issued
2013-08-30
Sprache
English
Author(s)
Herwig, Heinz  
Schmandt, Bastian  
Institut
Technische Thermodynamik M-21  
Thermofluiddynamik (M-21H)  
TORE-URI
http://hdl.handle.net/11420/6141
Journal
Fluid dynamics research  
Volume
45
Issue
5
Article Number
055507
Citation
Fluid Dynamics Research 5 (45): 055507 (2013)
Publisher DOI
10.1088/0169-5983/45/5/055507
Scopus ID
2-s2.0-84885338087
Publisher
Elsevier Science
Internal and external flows are characterized by friction factors and drag coefficients, respectively. Their definitions are based on pressure drop and drag force and thus are very different in character. From a thermodynamics point of view in both cases dissipation occurs which can uniformly be related to the entropy generation in the flow field. Therefore we suggest to account for losses in the flow field by friction factors and drag coefficients that are based on the overall entropy generation due to the dissipation in the internal and external flow fields. This second law analysis (SLA) has been applied to internal flows in many studies already. Examples of this flow category are given together with new cases of external flows, also treated by the general SLA-approach. © 2013 The Japan Society of Fluid Mechanics and IOP Publishing Ltd.
DDC Class
600: Technik
620: Ingenieurwissenschaften
More Funding Information
Deutsche Forschungsgemeinschaft, DFG