Journal article
Flow Structure around Bridge Piers of Varying Geometrical Complexity
Journal of Hydraulic Engineering, Vol.139(8), pp.812-826
08/01/2013
DOI: 10.1061/(ASCE)HY.1943-7900.0000742
Abstract
AbstractPiers with back-to-back stems or columns and piers for which part of the foundation becomes exposed as a result of the development of scour over large periods of time or because of severe flood events are fairly common at bridge waterways. The present paper uses eddy-resolving numerical simulations to study flow and turbulence structure at piers of complex shape and/or with multiple components. In particular, the study considers cases with one and two back-to-back pier columns for which the section of the main column is neither circular nor rectangular. In addition to a design case for which the foundation of each pier column is submerged, the study analyzes a case when scour exposes part of the foundation of the main column. The results show that the shape and size of the pier column have a significant effect on the spatial and temporal distributions of the bed friction velocity induced by the horseshoe vortex system. The large-scale shedding behind the main column greatly influences flow structure and increases bed friction velocity around the downstream column for piers with two back-to-back columns that are aligned with the incoming flow direction. The present study shows that the presence of large-scale unsteady coherent structures in the vicinity of the bed around piers of complex shapes results in very complex distributions of the bed friction velocity and in large-scale temporal oscillations of the bed friction velocity. The results of eddy-resolving simulations strongly suggest the need to account for the effect of these large-scale oscillations around the mean value when bed friction velocity distributions are used to estimate the flux of entrained sediment in movable bed simulations that do not resolve the large-scale turbulent flow structures.
Details
- Title: Subtitle
- Flow Structure around Bridge Piers of Varying Geometrical Complexity
- Creators
- Wen-Yi Chang - Associate Researcher, National Center for High-Performance Computing, National Applied Research Laboratories, Hsinchu 30076, . E-mailGeorge Constantinescu - Univ. of Iowa Associate Professor, Civil and Environmental Engineering, IIHR-Hydroscience and Engineering, , Stanley Hydraulics Laboratory, Iowa City, IA 52242 (corresponding author). E-mailHo-Cheng Lien - Associate Researcher, National Center for High-Performance Computing, National Applied Research Laboratories, Hsinchu 30076, . E-mailWhey-Fone Tsai - Senior Researcher, National Center for High-Performance Computing, National Applied Research Laboratories, Hsinchu 30076, . E-mailJihn-Sung Lai - National Taiwan Univ. Research Fellow, Hydrotech Research Institute, Dept. of Bioenvironmental Systems Engineering, , Hsinchu 30076, . E-mailChin-Hsiung Loh - National Taiwan Univ. Professor, Dept. of Civil Engineering, , Hsinchu 30076, . E-mail
- Resource Type
- Journal article
- Publication Details
- Journal of Hydraulic Engineering, Vol.139(8), pp.812-826
- DOI
- 10.1061/(ASCE)HY.1943-7900.0000742
- ISSN
- 0733-9429
- eISSN
- 1943-7900
- Publisher
- American Society of Civil Engineers
- Language
- English
- Date published
- 08/01/2013
- Academic Unit
- Civil and Environmental Engineering
- Record Identifier
- 9983992066902771
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