Four-Dimensional Measurements of the Structure of Dissipative Scales in an Aqueous Near-Isotropic Turbulence

Jian Lin Jiang, S. S. Shy, T. S. Yang, J. H. Lee

研究成果: 書貢獻/報告類型章節

摘要

This note reports a particle image velocimetry technique for obtaining fully resolved measurements of the velocity field u(x,y,z,t) throughout a four- dimensional spatiotemporal region on the inner scale in a near-isotropic stationary turbulence generated by a pair of vibrating grids in a water tank. The method uses a high-speed successive sweeping laser sheet and two synchronous high-speed stereo CCD cameras combined with a fast image processing system, so that the underlying full spatial velocity field and the corresponding kinetic energy dissipation rate field can be determined. Measurements confirm that the distribution of the dissipation rate field is a highly intermittent phenomenon, in which high kinetic energy dissipation rates occur infrequently and are correlated with regions of high principal strain rate, in consistent with the results found by Sreenivasan & Antonia. The fine structures of the kinetic energy dissipation rate field in the present turbulence are complex, containing line-like, blob-like, and sheet-like structures with the diameter, size, and thickness ranging in scale from 1 to 6 Kolmogorov scale (η) with a mean of about 3η. These data are useful for investigating topological features of fine structure turbulence.
原文中文
主出版物標題IUTAM Symposium on Reynolds Number Scaling in Turbulent Flow: Proceedings of the IUTAM Symposium held in Princeton, NJ, U.S.A., 11–13 September 2002
編輯Alexander J. Smits
出版地Dordrecht
發行者Springer Netherlands
頁面207-213
頁數7
ISBN(列印)978-94-007-0997-3
DOIs
出版狀態已發佈 - 2004

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