Behaviour of the Reynolds stress on rough walls |
| |
Authors: | A Mazouz L Labraga C Tournier |
| |
Institution: | (1) Laboratoire de Mécanique des Fluides, Université de Valenciennes et du Hainaut Cambrésis, Le Mont Houy B.P. 311, F-59304 Valenciennes Cédex, France |
| |
Abstract: | Quadrant analysis is used to study the contributions, associated to the four quadrants of the (u,v) plane, to the production of the turbulent shear stress on rough walls. The measurements are described for a fully developed
turbulent flow between two rough plates with varying the parameterλ
z(span/height ratio of roughness elements). The application of this technique indicates that the (Q
2) events (ejections) and (Q
4) events (sweeps) cause an intense production of the Reynolds stress —ρ
as compared with the (Q
1) and (Q
3) quadrants. The (Q
2) contribution to the Reynolds stress depends on the geometry factorλ
z.
Variation of the parameterλ
zaffects the distributions of
and
forH⩽3, whereH is a particular threshold. Comparison with boundary layer flow shows that the region 0.2⩽y/h⩽0.7 is characterized by a Reynolds stress production, independent of the flow nature. The third moment of the longitudinal
velocity fluctuations is found to be sensitive to the surface roughness. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|