Experimental study of extreme shear stress for shallow flow under simulated rainfall |
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| Authors: | Jau‐Yau Lu Jun‐Ji Lee Tai‐Fang Lu Jian‐Hao Hong |
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| Institution: | 1. Department of Civil Engineering, National Chung Hsing University, Taichung, Taiwan, R.O.C.;2. Department of Statistics and Informatics Science, Providence University, Taichung, Taiwan, R.O.C. |
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| Abstract: | The raindrop impact and overland flow are two major factors causing soil detachment and particle transportation. In this study, the turbulent characteristics of the shallow rain‐impacted water flow were investigated using a 2‐D fibre‐optic laser Doppler velocimetry (FLDV) and an artificial rainfall simulator. The fluctuating turbulent shear stress was computed using digital data processing techniques. The experimental data showed that the Reynolds shear stress follows a probability distribution with heavy tails. The tail probability increases with an increase of rainfall intensity or raindrop diameter, and it decreases with an increase of Reynolds number. A modified empirical equation was derived using both the raindrop diameter and rainfall intensity as independent variables to provide a better prediction of the Darcy‐Weisbach friction coefficient f under rainfall conditions. Copyright © 2009 John Wiley & Sons, Ltd. |
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| Keywords: | raindrop impact turbulent shear stress Darcy‐Weisbach friction coefficient |
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