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Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law
In the presented article a generalization of Newton’s formula for the shear stress in a fluid is carried out by giving it a power-law form. After the introduction of the corresponding strain rate tensor, a generalization is made to the spatial case of flow and the rheological relation is presented i...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9415900/ https://www.ncbi.nlm.nih.gov/pubmed/36015565 http://dx.doi.org/10.3390/polym14163308 |
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author | Nikushchenko, Dmitry Pavlovsky, Valery Nikushchenko, Elena |
author_facet | Nikushchenko, Dmitry Pavlovsky, Valery Nikushchenko, Elena |
author_sort | Nikushchenko, Dmitry |
collection | PubMed |
description | In the presented article a generalization of Newton’s formula for the shear stress in a fluid is carried out by giving it a power-law form. After the introduction of the corresponding strain rate tensor, a generalization is made to the spatial case of flow and the rheological relation is presented in tensor form. Depending on the power value in this rheological ratio, one can come either to a description of a laminar flow regime (in the form of Navier–Stokes equations), or to a description of the flow in turbulent regime. In the latter case, a set of differential equations with the no-slip boundary condition is specified, which is significantly different from that for the laminar flow regime, but which also allows one to obtain analytical solutions for simple shear flows and obtain the Blasius resistance law for the flow in a pipe. Therefore, the considered approach to solving problems of turbulent flows compares favorably with modern differential turbulence models. Solutions are given for simple shear flows of a fluid, when there is only one longitudinal component of the velocity, which depends on the transversal coordinate only. These solutions in terms of velocity profiles and resistance coefficients are in satisfactory agreement with the experimental data. |
format | Online Article Text |
id | pubmed-9415900 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-94159002022-08-27 Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law Nikushchenko, Dmitry Pavlovsky, Valery Nikushchenko, Elena Polymers (Basel) Article In the presented article a generalization of Newton’s formula for the shear stress in a fluid is carried out by giving it a power-law form. After the introduction of the corresponding strain rate tensor, a generalization is made to the spatial case of flow and the rheological relation is presented in tensor form. Depending on the power value in this rheological ratio, one can come either to a description of a laminar flow regime (in the form of Navier–Stokes equations), or to a description of the flow in turbulent regime. In the latter case, a set of differential equations with the no-slip boundary condition is specified, which is significantly different from that for the laminar flow regime, but which also allows one to obtain analytical solutions for simple shear flows and obtain the Blasius resistance law for the flow in a pipe. Therefore, the considered approach to solving problems of turbulent flows compares favorably with modern differential turbulence models. Solutions are given for simple shear flows of a fluid, when there is only one longitudinal component of the velocity, which depends on the transversal coordinate only. These solutions in terms of velocity profiles and resistance coefficients are in satisfactory agreement with the experimental data. MDPI 2022-08-14 /pmc/articles/PMC9415900/ /pubmed/36015565 http://dx.doi.org/10.3390/polym14163308 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Nikushchenko, Dmitry Pavlovsky, Valery Nikushchenko, Elena Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law |
title | Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law |
title_full | Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law |
title_fullStr | Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law |
title_full_unstemmed | Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law |
title_short | Analytical Solutions for Simple Turbulent Shear Flows on a Basis of a Generalized Newton’s Law |
title_sort | analytical solutions for simple turbulent shear flows on a basis of a generalized newton’s law |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9415900/ https://www.ncbi.nlm.nih.gov/pubmed/36015565 http://dx.doi.org/10.3390/polym14163308 |
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