Proceedings of the KSME Conference (대한기계학회:학술대회논문집)
- 2003.11a
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- Pages.610-615
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- 2003
Identification of the three-dimensional topology of hairpin packet structures in turbulent boundary layers
난류경계층의 헤어핀 다발구조에 대한 3차원 토폴로지 규명
- Published : 2003.11.05
Abstract
This experiment has been carried out to find the structure of turbulent boundary layer with instantaneous velocity fields obtained in stream-wall-normal planes using a stereo-PIV (Particle Image Velocimetry) method. And it has been measured perpendicular plane and horizontal plane with hairpin vortex structure by Reynolds number change and made third dimension shape for section of horizontal plane through stereo-PIV. In the outer layer hairpin vortices occur in streamwise-aligned packets that propagate with small velocity dispersion. A streaky structure is composed of counter-rotating vortex. According as y+ increases, streaky structure's interval space decrease, and it shows that hairpin shape of prior research is vertified. The objective of the present research is to gain a better understanding of coherent structures in the outer of wall turbulence by experimentally examining coherent structures.
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