Unified criterion for clear-water local scour induced by junction flows and wall jets
Local scour in a sediment bed varies depending on the type, size and shape of hydraulic structures, and the properties of approach flow and sediment particles. Published studies are hitherto confined primarily to empirical experiments based on particular types of hydraulic structure and there is alm...
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sg-ntu-dr.10356-1536742022-01-07T05:24:56Z Unified criterion for clear-water local scour induced by junction flows and wall jets Cheng, Nian-Sheng Lu, Yesheng Wei, Maoxing Chiew, Yee-Meng School of Civil and Environmental Engineering Engineering::Civil engineering Abutment Bridge Pier Local scour in a sediment bed varies depending on the type, size and shape of hydraulic structures, and the properties of approach flow and sediment particles. Published studies are hitherto confined primarily to empirical experiments based on particular types of hydraulic structure and there is almost no comparison of scour amongst different types of hydraulic structures. This study aims to provide an attempt to unify different types of clear-water scour based on a new length scale, which is proposed to characterize the size of the large-scale flow structure that governs scouring processes. The new length scale serves as a generalized hydraulic radius, which is applicable for all types of clear-water scour related to junction flows at bridge piers and abutments, and wall jets including culverts. The analysis indicates that when normalized with the new length scale, the equilibrium scour depths can be described with a unified function of the densimetric Froude number, regardless of different scour types. In addition, this study also shows that the proposed function varies with the scour efficiency, in a fashion resembling the bedload function in the range of low to high transport regimes. This finding, which is founded on solid physical grounds, reveals that different kinds of local scour phenomena can be interpreted in unison rather than based on the individual type of hydraulic structures. Published version The authors would gratefully acknowl-edge the financial support from the National Natural Science Foundation of China (Grant No. 51979242). 2022-01-07T05:24:56Z 2022-01-07T05:24:56Z 2021 Journal Article Cheng, N., Lu, Y., Wei, M. & Chiew, Y. (2021). Unified criterion for clear-water local scour induced by junction flows and wall jets. Water Resources Research, 57(5), e2020WR028804-. https://dx.doi.org/10.1029/2020WR028804 0043-1397 https://hdl.handle.net/10356/153674 10.1029/2020WR028804 2-s2.0-85106755317 5 57 e2020WR028804 en Water Resources Research © 2021 American Geophysical Union. All rights reserved. This paper was published in Water Resources Research and is made available with permission of American Geophysical Union. application/pdf |
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Engineering::Civil engineering Abutment Bridge Pier Cheng, Nian-Sheng Lu, Yesheng Wei, Maoxing Chiew, Yee-Meng Unified criterion for clear-water local scour induced by junction flows and wall jets |
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Local scour in a sediment bed varies depending on the type, size and shape of hydraulic structures, and the properties of approach flow and sediment particles. Published studies are hitherto confined primarily to empirical experiments based on particular types of hydraulic structure and there is almost no comparison of scour amongst different types of hydraulic structures. This study aims to provide an attempt to unify different types of clear-water scour based on a new length scale, which is proposed to characterize the size of the large-scale flow structure that governs scouring processes. The new length scale serves as a generalized hydraulic radius, which is applicable for all types of clear-water scour related to junction flows at bridge piers and abutments, and wall jets including culverts. The analysis indicates that when normalized with the new length scale, the equilibrium scour depths can be described with a unified function of the densimetric Froude number, regardless of different scour types. In addition, this study also shows that the proposed function varies with the scour efficiency, in a fashion resembling the bedload function in the range of low to high transport regimes. This finding, which is founded on solid physical grounds, reveals that different kinds of local scour phenomena can be interpreted in unison rather than based on the individual type of hydraulic structures. |
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School of Civil and Environmental Engineering |
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School of Civil and Environmental Engineering Cheng, Nian-Sheng Lu, Yesheng Wei, Maoxing Chiew, Yee-Meng |
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Article |
author |
Cheng, Nian-Sheng Lu, Yesheng Wei, Maoxing Chiew, Yee-Meng |
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Cheng, Nian-Sheng |
title |
Unified criterion for clear-water local scour induced by junction flows and wall jets |
title_short |
Unified criterion for clear-water local scour induced by junction flows and wall jets |
title_full |
Unified criterion for clear-water local scour induced by junction flows and wall jets |
title_fullStr |
Unified criterion for clear-water local scour induced by junction flows and wall jets |
title_full_unstemmed |
Unified criterion for clear-water local scour induced by junction flows and wall jets |
title_sort |
unified criterion for clear-water local scour induced by junction flows and wall jets |
publishDate |
2022 |
url |
https://hdl.handle.net/10356/153674 |
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1722355299209183232 |