Independent component analysis of streamwise velocity fluctuations in turbulent channel flows

IF 3.2 3区工程技术 Q2 MECHANICS Theoretical and Applied Mechanics Letters Pub Date : 2022-05-01 DOI:10.1016/j.taml.2022.100349

Ting Wu , Guowei He

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引用次数: 3

Abstract

Independent component analysis (ICA) is used to study the multiscale localised modes of streamwise velocity fluctuations in turbulent channel flows. ICA aims to decompose signals into independent modes, which may induce spatially localised objects. The height and size are defined to quantify the spatial position and extension of these ICA modes, respectively. In contrast to spatially extended proper orthogonal decomposition (POD) modes, ICA modes are typically localised in space, and the energy of some modes is distributed across the near-wall region. The sizes of ICA modes are multiscale and are approximately proportional to their heights. ICA modes can also help to reconstruct the statistics of turbulence, particularly the third-order moment of velocity fluctuations, which is related to the strongest Reynolds shear-stress-producing events. The results reported in this paper indicate that the ICA method may connect statistical descriptions and structural descriptions of turbulence.

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紊流河道中沿流速度波动的独立分量分析

采用独立分量分析(ICA)研究了紊流沟道中顺流速度波动的多尺度局域模态。ICA的目的是将信号分解成独立的模式，这些模式可能会诱导出空间局部化的对象。定义高度和大小分别用于量化这些ICA模式的空间位置和扩展。与空间扩展固有正交分解(POD)模态相比，ICA模态通常在空间上是局域化的，某些模态的能量分布在近壁区域。ICA模态的大小是多尺度的，并且与它们的高度近似成正比。ICA模式还可以帮助重建湍流的统计数据，特别是速度波动的三阶矩，这与最强的雷诺兹剪切应力产生事件有关。本文的结果表明，ICA方法可以将湍流的统计描述和结构描述结合起来。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Theoretical and Applied Mechanics Letters MECHANICS-

CiteScore

6.20

自引率

2.90%

发文量

545

审稿时长

12 weeks

期刊介绍： An international journal devoted to rapid communications on novel and original research in the field of mechanics. TAML aims at publishing novel, cutting edge researches in theoretical, computational, and experimental mechanics. The journal provides fast publication of letter-sized articles and invited reviews within 3 months. We emphasize highlighting advances in science, engineering, and technology with originality and rapidity. Contributions include, but are not limited to, a variety of topics such as: • Aerospace and Aeronautical Engineering • Coastal and Ocean Engineering • Environment and Energy Engineering • Material and Structure Engineering • Biomedical Engineering • Mechanical and Transportation Engineering • Civil and Hydraulic Engineering Theoretical and Applied Mechanics Letters (TAML) was launched in 2011 and sponsored by Institute of Mechanics, Chinese Academy of Sciences (IMCAS) and The Chinese Society of Theoretical and Applied Mechanics (CSTAM). It is the official publication the Beijing International Center for Theoretical and Applied Mechanics (BICTAM).