A Constitutive Equation of Turbulence

Even though applications of direct numerical simulations are on the rise, today the most usual method to solve turbulence problems is still to apply a closure scheme of a defined order. It is not the case that a rising order of a turbulence model is always related to a quality improvement. Even more...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Peter W. Egolf, Kolumban Hutter
Formato: article
Lenguaje:EN
Publicado: MDPI AG 2021
Materias:
Acceso en línea:https://doaj.org/article/ef956db5e9eb4c1688701c78864ad797
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
id oai:doaj.org-article:ef956db5e9eb4c1688701c78864ad797
record_format dspace
spelling oai:doaj.org-article:ef956db5e9eb4c1688701c78864ad7972021-11-25T17:31:49ZA Constitutive Equation of Turbulence10.3390/fluids61104142311-5521https://doaj.org/article/ef956db5e9eb4c1688701c78864ad7972021-11-01T00:00:00Zhttps://www.mdpi.com/2311-5521/6/11/414https://doaj.org/toc/2311-5521Even though applications of direct numerical simulations are on the rise, today the most usual method to solve turbulence problems is still to apply a closure scheme of a defined order. It is not the case that a rising order of a turbulence model is always related to a quality improvement. Even more, a conceptual advantage of applying a lowest order turbulence model is that it represents the analogous method to the procedure of introducing a <i>constitutive equation</i> which has brought success to many other areas of physics. First order turbulence models were developed in the 1920s and today seem to be outdated by newer and more sophisticated mathematical-physical closure schemes. However, with the new knowledge of fractal geometry and fractional dynamics, it is worthwhile to step back and reinvestigate these lowest order models. As a result of this and simultaneously introducing generalizations by multiscale analysis, the first order, nonlinear, nonlocal, and fractional Difference-Quotient Turbulence Model (DQTM) was developed. In this partial review article of work performed by the authors, by theoretical considerations and its applications to turbulent flow problems, evidence is given that the DQTM is the missing (apparent) constitutive equation of turbulent shear flows.Peter W. EgolfKolumban HutterMDPI AGarticleNewton’s law of viscosityReynolds shear stressKraichnan’s direct interaction approximationBoussinesq’s closure approximationPrandtl’s mixing-length modeldifference-quotient turbulence modelThermodynamicsQC310.15-319Descriptive and experimental mechanicsQC120-168.85ENFluids, Vol 6, Iss 414, p 414 (2021)
institution DOAJ
collection DOAJ
language EN
topic Newton’s law of viscosity
Reynolds shear stress
Kraichnan’s direct interaction approximation
Boussinesq’s closure approximation
Prandtl’s mixing-length model
difference-quotient turbulence model
Thermodynamics
QC310.15-319
Descriptive and experimental mechanics
QC120-168.85
spellingShingle Newton’s law of viscosity
Reynolds shear stress
Kraichnan’s direct interaction approximation
Boussinesq’s closure approximation
Prandtl’s mixing-length model
difference-quotient turbulence model
Thermodynamics
QC310.15-319
Descriptive and experimental mechanics
QC120-168.85
Peter W. Egolf
Kolumban Hutter
A Constitutive Equation of Turbulence
description Even though applications of direct numerical simulations are on the rise, today the most usual method to solve turbulence problems is still to apply a closure scheme of a defined order. It is not the case that a rising order of a turbulence model is always related to a quality improvement. Even more, a conceptual advantage of applying a lowest order turbulence model is that it represents the analogous method to the procedure of introducing a <i>constitutive equation</i> which has brought success to many other areas of physics. First order turbulence models were developed in the 1920s and today seem to be outdated by newer and more sophisticated mathematical-physical closure schemes. However, with the new knowledge of fractal geometry and fractional dynamics, it is worthwhile to step back and reinvestigate these lowest order models. As a result of this and simultaneously introducing generalizations by multiscale analysis, the first order, nonlinear, nonlocal, and fractional Difference-Quotient Turbulence Model (DQTM) was developed. In this partial review article of work performed by the authors, by theoretical considerations and its applications to turbulent flow problems, evidence is given that the DQTM is the missing (apparent) constitutive equation of turbulent shear flows.
format article
author Peter W. Egolf
Kolumban Hutter
author_facet Peter W. Egolf
Kolumban Hutter
author_sort Peter W. Egolf
title A Constitutive Equation of Turbulence
title_short A Constitutive Equation of Turbulence
title_full A Constitutive Equation of Turbulence
title_fullStr A Constitutive Equation of Turbulence
title_full_unstemmed A Constitutive Equation of Turbulence
title_sort constitutive equation of turbulence
publisher MDPI AG
publishDate 2021
url https://doaj.org/article/ef956db5e9eb4c1688701c78864ad797
work_keys_str_mv AT peterwegolf aconstitutiveequationofturbulence
AT kolumbanhutter aconstitutiveequationofturbulence
AT peterwegolf constitutiveequationofturbulence
AT kolumbanhutter constitutiveequationofturbulence
_version_ 1718412261045829632