文献类型：期刊文献

英文题名：Coherent structures in a compressible turbulent plane jet

作者：Liu, Qilin[1];Lai, Huanxin[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

年份：2021

卷号：33

期号：10

外文期刊名：PHYSICS OF FLUIDS

收录：;EI(收录号：20214211032039);WOS:【SCI-EXPANDED(收录号:WOS:000756198200036)】；

基金：The authors are grateful to the National Natural Science Foundation of China (NSFC) for funding this study under Grant No. 51976061.

语种：英文

外文关键词：Principal component analysis

摘要：Coherent structures represented by proper orthogonal decomposition (POD) modes from large-eddy simulation of a compressible plane jet are analyzed. The leading POD modes of the fluctuating velocity components u', v', and w', and the pressure fluctuation p' are considered. Spatial and temporal features of these modes are analyzed by the modes and the spectra of the temporal coefficients, respectively. Interactions between leading modes of u', v', and w' and the relationship between the modes of u', v', and w' and of the p' are discussed. The results show that the leading mode of u' is in the shape of longitudinal stripes, and the mode is dominated by the jet column frequency St(c). For spanwise fluctuation w', the leading modes are a pair of modes in the shape of a train of ridges along streamwise, and they are dominated by the fundamental frequency St(0). The leading modes for v' are a pair of modes in a row of ribs. For the dominant frequencies of the v' modes, suppression of subharmonic frequency at St(0)/2 and formation of sideband frequencies around (St(0) +/- St(c))/2 are observed. These spatiotemporal features suggest the mode of v' is modulated by the modes of u' and w'. Both the leading modes of p' and of v' are in the shape of puffs outside the averaged shear layer. These puff modes are related as an oscillation system, which is confirmed by the spectral-POD modes. Published under an exclusive license by AIP Publishing.