How to Determine Losses in a Flow Field: A Paradigm Shift towards the Second Law Analysis
Institute for Thermo-Fluid Dynamics , Hamburg University of Technology, Denickestr. 17, D-21073 Hamburg, Germany
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Entropy 2014, 16(6), 2959-2989; https://doi.org/10.3390/e16062959
Received: 26 February 2014 / Revised: 2 April 2014 / Accepted: 20 May 2014 / Published: 26 May 2014
(This article belongs to the Special Issue Advances in Applied Thermodynamics)
Assuming that CFD solutions will be more and more used to characterize losses in terms of drag for external flows and head loss for internal flows, we suggest to replace single-valued data, like the drag force or a pressure drop, by field information about the losses. These information are gained when the entropy generation in the flow field is analyzed, an approach that often is called second law analysis (SLA), referring to the second law of thermodynamics. We show that this SLA approach is straight-forward, systematic and helpful when it comes to the physical interpretation of the losses in a flow field. Various examples are given, including external and internal flows, two phase flow, compressible flow and unsteady flow. Finally, we show that an energy transfer within a certain process can be put into a broader perspective by introducing the entropic potential of an energy.
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Keywords:
second law analysis; entropy generation; entropic potential
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MDPI and ACS Style
Herwig, H.; Schmandt, B. How to Determine Losses in a Flow Field: A Paradigm Shift towards the Second Law Analysis. Entropy 2014, 16, 2959-2989. https://doi.org/10.3390/e16062959
AMA Style
Herwig H, Schmandt B. How to Determine Losses in a Flow Field: A Paradigm Shift towards the Second Law Analysis. Entropy. 2014; 16(6):2959-2989. https://doi.org/10.3390/e16062959
Chicago/Turabian StyleHerwig, Heinz; Schmandt, Bastian. 2014. "How to Determine Losses in a Flow Field: A Paradigm Shift towards the Second Law Analysis" Entropy 16, no. 6: 2959-2989. https://doi.org/10.3390/e16062959
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