Turbulence structures in flows over a submerged weir

Chaewoong Ban; Sung Uk Choi

Turbulence structures in flows over a submerged weir

Chaewoong Ban, Sung Uk Choi

Department of Civil and Environmental Engineering

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

1 Citation (Scopus)

Abstract

Local scour downstream of a weir is common problem, which can result in serious damage to the weir itself and instability of the downstream channel. Local scour downstream of the weir can be attributed to the force exerted on the bed by highly 3D flows generated by the weir. Specifically, such flows are characterized by the separated shear layer and unsteady large-scale coherent structures. This study presented the results of large eddy simulation (LES) of the flow over a submerged weir to investigate the characteristics of the turbulent flows downstream of the weir. LES was applied to the flat bed (FB) case and the deformed bed (DB) case with a scour hole. Time-averaged velocity was compared with measured data for validating computations. Coherent structures near the bed were examined using uw quadrant analysis. For the FB case, the splats occur frequently with strong sweep event near the reattachment point. On the contrary, the splats rarely occur and relatively weak sweep events remain near the reattachment point for the DB case.

Original language	English
Title of host publication	River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics
Editors	Wim Uijttewaal, Mario J. Franca, Daniel Valero, Victor Chavarrias, Claudia Ylla Arbos, Ralph Schielen, Ralph Schielen, Alessandra Crosato
Publisher	CRC Press/Balkema
Pages	178-184
Number of pages	7
ISBN (Electronic)	9780367627737
Publication status	Published - 2020
Event	10th Conference on Fluvial Hydraulics, River Flow 2020 - Virtual, Online, Netherlands Duration: 2020 Jul 7 → 2020 Jul 10

Publication series

Name	River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics

Conference

Conference	10th Conference on Fluvial Hydraulics, River Flow 2020
Country/Territory	Netherlands
City	Virtual, Online
Period	20/7/7 → 20/7/10

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (NRF2017R1A2A2A05069836).

Publisher Copyright:
© 2020 Taylor & Francis Group, London

All Science Journal Classification (ASJC) codes

Fluid Flow and Transfer Processes
Geotechnical Engineering and Engineering Geology

Cite this

Ban, C., & Choi, S. U. (2020). Turbulence structures in flows over a submerged weir. In W. Uijttewaal, M. J. Franca, D. Valero, V. Chavarrias, C. Y. Arbos, R. Schielen, R. Schielen, & A. Crosato (Eds.), River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics (pp. 178-184). (River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics). CRC Press/Balkema.

Ban, Chaewoong ; Choi, Sung Uk. / Turbulence structures in flows over a submerged weir. River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics. editor / Wim Uijttewaal ; Mario J. Franca ; Daniel Valero ; Victor Chavarrias ; Claudia Ylla Arbos ; Ralph Schielen ; Ralph Schielen ; Alessandra Crosato. CRC Press/Balkema, 2020. pp. 178-184 (River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics).

@inproceedings{e65864e374a44f359cc7df89381f73ae,

title = "Turbulence structures in flows over a submerged weir",

abstract = "Local scour downstream of a weir is common problem, which can result in serious damage to the weir itself and instability of the downstream channel. Local scour downstream of the weir can be attributed to the force exerted on the bed by highly 3D flows generated by the weir. Specifically, such flows are characterized by the separated shear layer and unsteady large-scale coherent structures. This study presented the results of large eddy simulation (LES) of the flow over a submerged weir to investigate the characteristics of the turbulent flows downstream of the weir. LES was applied to the flat bed (FB) case and the deformed bed (DB) case with a scour hole. Time-averaged velocity was compared with measured data for validating computations. Coherent structures near the bed were examined using uw quadrant analysis. For the FB case, the splats occur frequently with strong sweep event near the reattachment point. On the contrary, the splats rarely occur and relatively weak sweep events remain near the reattachment point for the DB case.",

author = "Chaewoong Ban and Choi, {Sung Uk}",

note = "Funding Information: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (NRF2017R1A2A2A05069836). Publisher Copyright: {\textcopyright} 2020 Taylor & Francis Group, London; 10th Conference on Fluvial Hydraulics, River Flow 2020 ; Conference date: 07-07-2020 Through 10-07-2020",

year = "2020",

language = "English",

series = "River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics",

publisher = "CRC Press/Balkema",

pages = "178--184",

editor = "Wim Uijttewaal and Franca, {Mario J.} and Daniel Valero and Victor Chavarrias and Arbos, {Claudia Ylla} and Ralph Schielen and Ralph Schielen and Alessandra Crosato",

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}

Ban, C & Choi, SU 2020, Turbulence structures in flows over a submerged weir. in W Uijttewaal, MJ Franca, D Valero, V Chavarrias, CY Arbos, R Schielen, R Schielen & A Crosato (eds), River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics. River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics, CRC Press/Balkema, pp. 178-184, 10th Conference on Fluvial Hydraulics, River Flow 2020, Virtual, Online, Netherlands, 20/7/7.

Turbulence structures in flows over a submerged weir. / Ban, Chaewoong; Choi, Sung Uk.

River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics. ed. / Wim Uijttewaal; Mario J. Franca; Daniel Valero; Victor Chavarrias; Claudia Ylla Arbos; Ralph Schielen; Ralph Schielen; Alessandra Crosato. CRC Press/Balkema, 2020. p. 178-184 (River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

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T1 - Turbulence structures in flows over a submerged weir

AU - Ban, Chaewoong

AU - Choi, Sung Uk

N1 - Funding Information: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (NRF2017R1A2A2A05069836). Publisher Copyright: © 2020 Taylor & Francis Group, London

PY - 2020

Y1 - 2020

N2 - Local scour downstream of a weir is common problem, which can result in serious damage to the weir itself and instability of the downstream channel. Local scour downstream of the weir can be attributed to the force exerted on the bed by highly 3D flows generated by the weir. Specifically, such flows are characterized by the separated shear layer and unsteady large-scale coherent structures. This study presented the results of large eddy simulation (LES) of the flow over a submerged weir to investigate the characteristics of the turbulent flows downstream of the weir. LES was applied to the flat bed (FB) case and the deformed bed (DB) case with a scour hole. Time-averaged velocity was compared with measured data for validating computations. Coherent structures near the bed were examined using uw quadrant analysis. For the FB case, the splats occur frequently with strong sweep event near the reattachment point. On the contrary, the splats rarely occur and relatively weak sweep events remain near the reattachment point for the DB case.

AB - Local scour downstream of a weir is common problem, which can result in serious damage to the weir itself and instability of the downstream channel. Local scour downstream of the weir can be attributed to the force exerted on the bed by highly 3D flows generated by the weir. Specifically, such flows are characterized by the separated shear layer and unsteady large-scale coherent structures. This study presented the results of large eddy simulation (LES) of the flow over a submerged weir to investigate the characteristics of the turbulent flows downstream of the weir. LES was applied to the flat bed (FB) case and the deformed bed (DB) case with a scour hole. Time-averaged velocity was compared with measured data for validating computations. Coherent structures near the bed were examined using uw quadrant analysis. For the FB case, the splats occur frequently with strong sweep event near the reattachment point. On the contrary, the splats rarely occur and relatively weak sweep events remain near the reattachment point for the DB case.

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M3 - Conference contribution

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BT - River Flow 2020 - Proceedings of the 10th Conference on Fluvial Hydraulics

A2 - Uijttewaal, Wim

A2 - Franca, Mario J.

A2 - Valero, Daniel

A2 - Chavarrias, Victor

A2 - Arbos, Claudia Ylla

A2 - Schielen, Ralph

A2 - Crosato, Alessandra

PB - CRC Press/Balkema

T2 - 10th Conference on Fluvial Hydraulics, River Flow 2020

Y2 - 7 July 2020 through 10 July 2020

ER -

Turbulence structures in flows over a submerged weir

Abstract

Publication series

Conference

Bibliographical note

All Science Journal Classification (ASJC) codes

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