Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence
Multiscale sample entropy analysis has been developed to quantify the complexity and the predictability of a time series, originally developed for physiological time series. In this study, the analysis was applied to the turbulence data. We measured time series data for the velocity fluctuation, in...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-02-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/23/2/245 |
| _version_ | 1797395847143489536 |
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| author | Ildoo Kim |
| author_facet | Ildoo Kim |
| author_sort | Ildoo Kim |
| collection | DOAJ |
| description | Multiscale sample entropy analysis has been developed to quantify the complexity and the predictability of a time series, originally developed for physiological time series. In this study, the analysis was applied to the turbulence data. We measured time series data for the velocity fluctuation, in either the longitudinal or transverse direction, of turbulent soap film flows at various locations. The research was to assess the feasibility of using the entropy analysis to qualitatively characterize turbulence, without using any conventional energetic analysis of turbulence. The study showed that the application of the entropy analysis to the turbulence data is promising. From the analysis, we successfully captured two important features of the turbulent soap films. It is indicated that the turbulence is anisotropic from the directional disparity. In addition, we observed that the most unpredictable time scale increases with the downstream distance, which is an indication of the decaying turbulence. |
| first_indexed | 2024-03-09T00:41:39Z |
| format | Article |
| id | doaj.art-61eaeaad69ee4c48bb4cdd938cf79cb8 |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-03-09T00:41:39Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-61eaeaad69ee4c48bb4cdd938cf79cb82023-12-11T17:47:10ZengMDPI AGEntropy1099-43002021-02-0123224510.3390/e23020245Multiscale Sample Entropy of Two-Dimensional Decaying TurbulenceIldoo Kim0Department of Mechanical and Electrical Engineering, Konkuk University, Chungju 27489, KoreaMultiscale sample entropy analysis has been developed to quantify the complexity and the predictability of a time series, originally developed for physiological time series. In this study, the analysis was applied to the turbulence data. We measured time series data for the velocity fluctuation, in either the longitudinal or transverse direction, of turbulent soap film flows at various locations. The research was to assess the feasibility of using the entropy analysis to qualitatively characterize turbulence, without using any conventional energetic analysis of turbulence. The study showed that the application of the entropy analysis to the turbulence data is promising. From the analysis, we successfully captured two important features of the turbulent soap films. It is indicated that the turbulence is anisotropic from the directional disparity. In addition, we observed that the most unpredictable time scale increases with the downstream distance, which is an indication of the decaying turbulence.https://www.mdpi.com/1099-4300/23/2/245sample entropydecaying turbulenceinformation content |
| spellingShingle | Ildoo Kim Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence Entropy sample entropy decaying turbulence information content |
| title | Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence |
| title_full | Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence |
| title_fullStr | Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence |
| title_full_unstemmed | Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence |
| title_short | Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence |
| title_sort | multiscale sample entropy of two dimensional decaying turbulence |
| topic | sample entropy decaying turbulence information content |
| url | https://www.mdpi.com/1099-4300/23/2/245 |
| work_keys_str_mv | AT ildookim multiscalesampleentropyoftwodimensionaldecayingturbulence |