期刊
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
卷 31, 期 6, 页码 974-984出版社
ELSEVIER SCIENCE INC
DOI: 10.1016/j.ijheatfluidflow.2010.02.023
关键词
PIV measurements; Porous wall; Permeability; Turbulent channel
In order to understand the effects of the wall permeability on turbulence near a porous wall flow field measurements are carried out for turbulent flows in a channel with a porous bottom wall by a two-component particle image velocimetry (PIV) system The porous media used are three kinds of foamed ceramics which have almost the same porosity (similar to 0 8) but different permeability It is confirmed that the flow becomes more turbulent over the porous wall and tends to be turbulent even at the bulk Reynolds number of Re-b = 1300 in the most permeable wall case tested Corresponding to laminar to turbulent transition the magnitude of the slip velocity on the porous wall is found to increase drastically in a narrow range of the Reynolds number To discuss the effects of the wall roughness and the wall permeability detailed discussions are made of zero-plane displacement and equivalent wall roughness for porous media The results clearly indicate that the turbulence is induced by not only the wall roughness but the wall permeability The measurements have also revealed that as Reb or the wall permeability increases the wall normal fluctuating velocity near the porous wall is enhanced due to the effects of the wall permeability This leads to the increase of the turbulent shear stress resulting in higher friction factors of turbulence over porous walls (C) 2010 Elsevier Inc All rights reserved
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据