To investigate the unsteady structure of secondary flow of a turbulent bounded jet in both frequency and physical spaces, the wavelet auto-correlation analysis was used to analyze the fluctuating velocities at various positions in a bounded jet. The wavelet auto-correlation analysis provides the auto-correlation characteristics of signals in terms of period and time delay. From the wavelet auto-correlation analysis, the branching structures in WR( ατ) reveal that a periodic large eddy motion contains the periodic small eddy motions. In the shear layer near the wall at X/b。 ＝8.0,Y/b 。=1.0 and Z/b。=1.9, the wavelet auto-correlation analysis may determine the period and the period and the location of the large-scale structure and the secondary flows.
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机译：为了研究湍流有界射流在频率和物理空间的二次流的非稳态结构，使用小波自相关分析来分析有界射流在各个位置的脉动速度。小波自相关分析提供了周期和时间延迟方面的信号自相关特性。从小波自相关分析，WR（ατ）中的分支结构表明，周期性大涡运动包含周期性小涡运动。在X / b ＝＝ 8.0，Y / b ＝ 1.0和Z / b ＝＝ 1.9的壁附近的剪切层中，小波自相关分析可以确定大尺度的周期和周期以及位置。结构和二次流。
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