Analysis of coherent structures in drag-reducing polymer solution flow based on proper orthogonal decomposition  

作　　者：CAI WeiHua LI FengChen ZHANG HongNa WANG Yue WANG Lu 

机构地区：[1]School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China [2]School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China [3]School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2012年第5期854-860,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.10872060);the Fundamental Research Funds for the Central Universities (Grant Nos.HIT.BRET1.2010008, HIT.NSRIF.2012070);the Doctoral Fund of Ministry of Education of China (Grant No.20112302110020);the China Postdoctoral Science Foundation (Grant No.2011M500652)

摘　　要：Direct numerical simulation(DNS) of forcing homogeneous isotropic turbulence with polymers was performed.In order to understand the polymers effect on turbulent coherent structures,proper orthogonal decomposition was performed to identify coherent structures based on DNS data,so as to analyze the remarkable difference due to the addition of polymers.The results showed that the numbers for eigenmodes required for capturing coherent structures were 32 and 24 for the Newtonian fluid and polymer solution flows,respectively,which means the decrease of the complexity in polymer solution flow.Through the POD energy spectrum,it was found that the turbulent kinetic energy is distributed onto a large number of eigenmodes whether in the Newtonian fluid flow or polymer solution flow,suggesting that polymer solution flow is still turbulent in one aspect.Besides,the POD eigenmodes were investigated,which found that the small-scale structures are inhibited in polymer solution flow.Direct numerical simulation （DNS） of forcing homogeneous isotropic turbulence with polymers was performed. In order to understand the polymers effect on turbulent coherent structures, proper orthogonal decomposition was performed to identify coherent structures based on DNS data, so as to analyze the remarkable difference due to the addition of polymers. The results showed that the numbers for eigenmodes required for capturing coherent structures were 32 and 24 for the Newtonian fluid and polymer solution flows, respectively, which means the decrease of the complexity in polymer solution flow. Through the POD energy spectrum, it was found that the turbulent kinetic energy is distributed onto a large number of eigenmodes whether in the Newtonian fluid flow or polymer solution flow, suggesting that polymer solution flow is still turbulent in one aspect. Besides, the POD eigenmodes were investigated, which found that the small-scale structures are inhibited in polymer solution flow.

关 键 词：coherent structures POLYMER drag reduction isotropic turbulence proper orthogonal decomposition 

分 类 号：O357.5[理学—流体力学] X169[理学—力学]