ID | 115272 |
タイトル別表記 | Analysis of laminar-turbulent transition process in mixing layer with various information measures
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著者 |
中村, 育雄
名古屋大学
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キーワード | Transition
Turbulence
Turbulent flow
Shannon entropy
Permutation entropy
Kullback-Leibler divergence
Probability density function
Mixing layer
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資料タイプ |
学術雑誌論文
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抄録 | 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.
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掲載誌名 |
日本機械学会論文集
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ISSN | 21879761
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出版者 | 日本機械学会
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巻 | 83
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号 | 845
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開始ページ | 16-00497
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発行日 | 2017-01-25
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EDB ID | |
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フルテキストファイル | |
言語 |
jpn
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著者版フラグ |
著者版
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部局 |
理工学系
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