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Contributions to Books:

B. Scheichl:
"Time-mean turbulent shear flows: classical modelling - asymptotic analysis - new perspectives";
in: "Fluid and Solid Mechanics (LTCC Advanced Mathematics Series)", 2; Sh. Bullet, T. Fearn, F.T. Smith (ed.); issued by: Queen Mary University of London, University College London; World Scientific, London, UK, 2016, (invited), ISBN: 978-1-78634-025-2, 71 - 108.



English abstract:

The challenge in a both rational and computational description of a developed turbulent flow in the spirit of time- or Reynolds averaging is mitigated considerably under the slender-layer assumption, which heuristically applies to majority of the flows having engineering relevance. Aside from internal flows as pipe and channel flows, here most notably external flow as boundary and free shear layers (such as jets, mixing layers, and wakes) attract attention. An analysis of this external shear flows can be viewed as most precise if it resorts to a minimum of assumptions reflecting physical intuition and/or modelling aspects. In this spirit, it commences with casting the---in striking contrast to what is known from the laminar counterparts of these flows---at first purely empirically observed slenderness of such flows at arbitrarily large globally formed Reynolds numbers into an asymptotic concept that copes with the various manifestations of such flows in full depths and breadths. This not only allows for recovering well-known semi-empirical laws but also lays the foundation for a deepened understanding of such flows as well as the discovery of novel and sometimes surprising results. Last not least, it provides the proper means for assessing the application of classical turbulence closures and hence the prediction of turbulent shear flows by virtue of computational fluid dynamics.


Keywords:
applied mathematics, asymptotic analysis, boundary layers, free-streamlines flows, perturbation techniques, turbulence, well-posedness


Electronic version of the publication:
http://publik.tuwien.ac.at/files/PubDat_240391.pdf


Created from the Publication Database of the Vienna University of Technology.