Conference
Transitional flow structures downstream of a backward-facing-step – An investigation using high resolution tomo PIV
| العنوان: | Transitional flow structures downstream of a backward-facing-step – An investigation using high resolution tomo PIV |
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| المؤلفون: | Schröder, Andreas, Schanz, Daniel, Heine, Benjamin, Dierksheide, Uwe |
| سنة النشر: | 2011 |
| المجموعة: | German Aerospace Center: elib - DLR electronic library |
| مصطلحات موضوعية: | Hubschrauber, Experimentelle Verfahren |
| الوصف: | Transitional flow structures in the shear layer of a laminar separation bubble downstream of a backward facing step (BFS) have been investigated by means of 2D-2C- und highly resolved 3D-3C- tomographic Particle Image Velocimetry (PIV) for Reynolds numbers between Re = 1420 and 3000 based on free-stream velocity U and step height h. By using an external acoustic excitation of the shear layer it was possible to arrange phase locked measurements of the wavy flow structures which emanate from instabilities according to Kelvin-Helmholtz (KH). Snapshots of fully 3D-3C velocity vector volumes show complex flow topologies of the non-linear part of the laminar-turbulent transition scenario. This part seems to be governed by hairpin-like, streamwise elongated vortices on top of the classical spanwise oriented 2- D waves. These vortices organize a rapid fluid exchange normal to the shear layer leading to turbulent reattachment of the flow and subsequent development of a turbulent boundary layer. |
| نوع الوثيقة: | conference object |
| اللغة: | unknown |
| Relation: | Schröder, Andreas und Schanz, Daniel und Heine, Benjamin und Dierksheide, Uwe (2011) Transitional flow structures downstream of a backward-facing-step – An investigation using high resolution tomo PIV. 9th International Symposium on Particle Image Velocimetry – PIV11, 2011-07-21 - 2011-07-23, Kobe, Japan. |
| الاتاحة: | https://elib.dlr.de/69845/ http://piv11.org/ |
| رقم الانضمام: | edsbas.8068D8BF |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |