Independent component analysis of streamwise velocity fluctuations in turbulent channel flows

作     者：Ting Wu Guowei He Ting Wu;Guowei He

作者机构：The State Key Laboratory of Nonlinear MechanicsInstitute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering SciencesUniversity of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Theoretical & Applied Mechanics Letters》 (力学快报（英文版）)

年 卷 期：2022年第12卷第4期

页      面：233-240页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by NSFC Basic Science Center Program for“Multiscale Problems in Nonlinear Mechanics”(No.11988102) National Natural Science Foundation of China(Nos.12002344,11232011 and 11572331) The authors would like to acknowledge the support from China Postdoctoral Science Foundation(No.2020M670478) the Strategic Priority Research Program(No.XDB22040104) the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(No.QYZDJ-SSW-SYS002) 

主　　题：Independent component analysis Turbulent channel flow Proper orthogonal decomposition Third-order moment Localised modes 

摘      要：Independent component analysis(ICA)is used to study the multiscale localised modes of streamwise velocity fluctuations in turbulent channel *** aims to decompose signals into independent modes,which may induce spatially localised *** height and size are defined to quantify the spatial position and extension of these ICA modes,*** 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 *** sizes of ICA modes are multiscale and are approximately proportional to their *** 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-stressproducing *** results reported in this paper indicate that the ICA method may connect statistical descriptions and structural descriptions of turbulence.