| Autor: |
Minh Do Khac, Khoa Dang-Tran, Thiên Hiêp-Lê, Claude Basdevant |
| Rok vydání: |
1998 |
| Předmět: |
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| Zdroj: |
Aerospace Science and Technology. 2:13-26 |
| ISSN: |
1270-9638 |
| DOI: |
10.1016/s0034-1223(98)80002-x |
| Popis: |
The temporal evolution of the three-dimensional structure of a plane mixing layer is investigated by Direct Numerical Simulation. Detailed visualizations are produced of the interactions between spanwise rolls, initiated by the Kelvin-Helmholtz instability, and the longitudinal ribs formed in the braid region, these interactions leading to the formation of smaller structures. Using 3D wavelet analysis, the spatial coherent structures of the vorticity field are related to the different scales produced in the Fourier spectrum. A detailed analysis of the vorticity amplification mechanisms by stretching is provided which supports the theoretical model given recently by Moffat, Kida and Ohkitani. The topologies of stretching and energy dissipation zones are related to the production of small scales during the rib formation and the bending of the rolls. This analysis suggests a possible generic mechanism for small scale production. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect