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ID 115272
Title Alternative
Analysis of laminar-turbulent transition process in mixing layer with various information measures
Author
Nakamura, Ikuo Nagoya University
Keywords
Transition
Turbulence
Turbulent flow
Shannon entropy
Permutation entropy
Kullback-Leibler divergence
Probability density function
Mixing layer
Content Type
Journal Article
Description
In the laminar-turbulent transition process of a mixing layer formed downstream of a two-dimensional nozzle exit, an analysis was performed based on various information measures. Shannon entropy, permutation entropy and Kullback-Leibler divergence were introduced, and former studies in which they were used in the turbulent analysis were then reviewed. In the present study, the probability distribution of time series of hot-wire output voltage data was obtained, then analyzed. The aim of the investigation was to clarify the effectiveness of the analysis for the transition and turbulent flow. In addition, equations which Shannon entropy must satisfy in the turbulent flow field were derived. The Shannon entropy of the fluctuating velocity changed monotonically in the downstream direction. Thus, it appears to measure the transition process in the mixing layer. The permutation entropy of the fluctuating velocity first increased, then decreased, then increased again, and decreased finally. It reflected the increase of the fluctuating velocity and change of fluctuation manner (from periodic to irregular fluctuation) during the transition process. The Kullback-Leibler divergence based on the probability density function of the fluctuating velocity increased first, then decreased downstream, and thus did not show a monotonic change during the transition process in the mixing layer.
Journal Title
Transactions of the JSME (in Japanese)
ISSN
21879761
Publisher
日本機械学会
Volume
83
Issue
845
Start Page
16-00497
Published Date
2017-01-25
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
jpn
TextVersion
Author
departments
Science and Technology