کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4526421 | 1323835 | 2008 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Parameterization of the logarithmic layer of double-averaged streamwise velocity profiles in gravel-bed river flows Parameterization of the logarithmic layer of double-averaged streamwise velocity profiles in gravel-bed river flows](/preview/png/4526421.png)
The logarithmic layer of double-averaged (in time and space) streamwise velocity profiles obtained from field measurements made in the Swiss rivers, Venoge and Chamberonne is parameterized and discussed. Velocity measurements were made using a 3D Acoustic Doppler Velocity Profiler. Both riverbeds are hydraulically rough, composed of coarse gravel, with relative submergences (h/D50) of 5.25 and 5.96, respectively. From the observations, the flow may be divided into three different layers: a roughness layer near the bed, an equivalent logarithmic layer and a surface or outer layer. It was found that a logarithmic law can describe the double-averaged profiles in the layer 0.30 < z/h < 0.75. The parameterization of the logarithmic law is discussed. Special emphasis is given to the geometric parameters roughness and zero-displacement heights and to the equivalent von Karman constant.
Journal: Advances in Water Resources - Volume 31, Issue 6, June 2008, Pages 915–925