Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic Turbulence

In isotropic turbulence, symmetry of different directions can reduce the number of independent components for velocity gradient tensors. In three-dimensional isotropic turbulence, the independent components under either incompressible or compressible conditions have already been analyzed in the lite...

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Main Authors: Chensheng Luo, Ping-Fan Yang, Le Fang
Format: Article
Language:English
Published: MDPI AG 2024-02-01
Series:Symmetry
Subjects:
Online Access:https://www.mdpi.com/2073-8994/16/2/175
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author Chensheng Luo
Ping-Fan Yang
Le Fang
author_facet Chensheng Luo
Ping-Fan Yang
Le Fang
author_sort Chensheng Luo
collection DOAJ
description In isotropic turbulence, symmetry of different directions can reduce the number of independent components for velocity gradient tensors. In three-dimensional isotropic turbulence, the independent components under either incompressible or compressible conditions have already been analyzed in the literature. However, for two-dimensional isotropic turbulence, they are still unclear. We derive rigorously the independent components for velocity gradient tensors of two-dimensional isotropic turbulence and give physical explanations. These theoretical results are validated using high-resolution direct numerical simulations (DNSs) of two-dimensional compressible turbulence. Results show that the present DNS setup is still not sufficient to capture the isotropy of third-order moments, suggesting that more investigations on determining the smallest scale and improving the numerical schemes for two-dimensional compressible turbulence are required.
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spelling doaj.art-d7f658f493e3455b86cdb06fe896a48a2024-02-23T15:35:55ZengMDPI AGSymmetry2073-89942024-02-0116217510.3390/sym16020175Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic TurbulenceChensheng Luo0Ping-Fan Yang1Le Fang2Laboratory of Complex System, Ecole Centrale de Pékin/School of General Engineering, Beihang University, Beijing 100191, ChinaThe State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaLaboratory of Complex System, Ecole Centrale de Pékin/School of General Engineering, Beihang University, Beijing 100191, ChinaIn isotropic turbulence, symmetry of different directions can reduce the number of independent components for velocity gradient tensors. In three-dimensional isotropic turbulence, the independent components under either incompressible or compressible conditions have already been analyzed in the literature. However, for two-dimensional isotropic turbulence, they are still unclear. We derive rigorously the independent components for velocity gradient tensors of two-dimensional isotropic turbulence and give physical explanations. These theoretical results are validated using high-resolution direct numerical simulations (DNSs) of two-dimensional compressible turbulence. Results show that the present DNS setup is still not sufficient to capture the isotropy of third-order moments, suggesting that more investigations on determining the smallest scale and improving the numerical schemes for two-dimensional compressible turbulence are required.https://www.mdpi.com/2073-8994/16/2/175two-dimensional turbulencecompressible turbulencevelocity gradient
spellingShingle Chensheng Luo
Ping-Fan Yang
Le Fang
Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic Turbulence
Symmetry
two-dimensional turbulence
compressible turbulence
velocity gradient
title Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic Turbulence
title_full Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic Turbulence
title_fullStr Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic Turbulence
title_full_unstemmed Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic Turbulence
title_short Low-Order Moments of Velocity Gradient Tensors in Two-Dimensional Isotropic Turbulence
title_sort low order moments of velocity gradient tensors in two dimensional isotropic turbulence
topic two-dimensional turbulence
compressible turbulence
velocity gradient
url https://www.mdpi.com/2073-8994/16/2/175
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