Characterization of horseshoe vortex in a developing scour hole at a cylindrical bridge pier
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摘要
Since local scour at bridge piers in rivers and estuaries is a major cause of bridge failure,estimation of the maximum local scour depth is of great importance to hydraulic and coastal engineers.Although numerous studies that focus on scour-depth prediction have been done and published,understanding of the flow and turbulence characteristics of the horseshoe vortex that drives the scour mechanism in a developing scour hole still is immature.This study aims to quantify the detailed turbulent flow field in a developing clear-water scour hole at a circular pier using Particle Image Velocimetry(PIV).The distributions of velocity fields,turbulence intensities,and Reynolds shear stresses of the horseshoe vortex that form in front of the pier at different scour stages(t = 0,0.5,1,12,24,and 48 h)are presented in this paper.During scour development,the horseshoe vortex system was found to evolve from one initially small vortex to three vortices.The strength and size of the main vortex are found to increase with increasing scour depth.The regions of both the maximum turbulence intensity and Reynolds shear stress are found to form at a location upstream of the main vortex,where the large turbulent eddies have the highest possibility of occurrence.Results from this study not only provide new insight into the complex flow-sediment interaction at bridge piers,but also provide valuable experimental databases for advanced numerical simulations.
Since local scour at bridge piers in rivers and estuaries is a major cause of bridge failure,estimation of the maximum local scour depth is of great importance to hydraulic and coastal engineers.Although numerous studies that focus on scour-depth prediction have been done and published,understanding of the flow and turbulence characteristics of the horseshoe vortex that drives the scour mechanism in a developing scour hole still is immature.This study aims to quantify the detailed turbulent flow field in a developing clear-water scour hole at a circular pier using Particle Image Velocimetry(PIV).The distributions of velocity fields,turbulence intensities,and Reynolds shear stresses of the horseshoe vortex that form in front of the pier at different scour stages(t = 0,0.5,1,12,24,and 48 h)are presented in this paper.During scour development,the horseshoe vortex system was found to evolve from one initially small vortex to three vortices.The strength and size of the main vortex are found to increase with increasing scour depth.The regions of both the maximum turbulence intensity and Reynolds shear stress are found to form at a location upstream of the main vortex,where the large turbulent eddies have the highest possibility of occurrence.Results from this study not only provide new insight into the complex flow-sediment interaction at bridge piers,but also provide valuable experimental databases for advanced numerical simulations.
Since local scour at bridge piers in rivers and estuaries is a major cause of bridge failure,estimation of the maximum local scour depth is of great importance to hydraulic and coastal engineers.Although numerous studies that focus on scour-depth prediction have been done and published,understanding of the flow and turbulence characteristics of the horseshoe vortex that drives the scour mechanism in a developing scour hole still is immature.This study aims to quantify the detailed turbulent flow field in a developing clear-water scour hole at a circular pier using Particle Image Velocimetry(PIV).The distributions of velocity fields,turbulence intensities,and Reynolds shear stresses of the horseshoe vortex that form in front of the pier at different scour stages(t = 0,0.5,1,12,24,and 48 h)are presented in this paper.During scour development,the horseshoe vortex system was found to evolve from one initially small vortex to three vortices.The strength and size of the main vortex are found to increase with increasing scour depth.The regions of both the maximum turbulence intensity and Reynolds shear stress are found to form at a location upstream of the main vortex,where the large turbulent eddies have the highest possibility of occurrence.Results from this study not only provide new insight into the complex flow-sediment interaction at bridge piers,but also provide valuable experimental databases for advanced numerical simulations.
引文
Apsilidis,N.,Diplas,P., Dancey,C.L.,&Bouratsis,P.(2015).Time-resolved flow dynamics and Reynolds number effects at a wall-cylinder junction.Journal of Fluid Mechanics,776,475-511.
Apsilidis,N.,Diplas,P.,Dancey,C.L,&Bouratsis,P.(2016).Effects of wall roughness on turbulent junction flow characteristics.Experiments in Fluids,57(1),12.
Bouratsis,P.,Diplas,P., Dancey,C.L,&Apsilidis,N.(2017).Quantitative spatiotemporal characterization of scour at the base of a cylinder.Water,9(3),227.
Chen,Q.,Qi,M.,Zhong,Q.,&Li,D.(2017).Experimental study on the multimodal dynamics of the turbulent horseshoe vortex system around a circular cylinder.Physics of Fluids,29(1),015106.
Cheng,N.S.,Chiew,Y.M.,&Chen,X.(2016).Scaling analysis of pier-scouring processes.Journal of Engineering Mechanics,142(8),06016005.
Chiew,Y.M.,&Melville,B.W.(1987).Local scour around bridge piers.Journal of Hydraulic Research,25(1),15-26.
Dargahi,B.(1987).Flow field and local scouring around a cylinder,137.Stockholm:Bulletin,Kungl Tekniska Hogskolan,Institution for Vattenbyggnad.
Dargahi,B.(1989).The turbulent flow field around a circular cylinder.Experiments in Fluids,8(1),1-12.
Dargahi,B.(1990).Controlling Mechanism of Local Scouring.Journal of Hydraulic Engineering,116(10),1197-1214.
Devenport,W.J.,&Simpson,R.L.(1990).Time-dependent and time-averaged turbulence structure near the nose of a wing-body junction.Journal of Fluid Mechanics,210, 23-55.
Dey,S.,&Raikar,R.(2007).Characteristics of horseshoe vortex in developing scour holes at piers.Journal of Hydraulic Engineering,133(4),399-413.
Ettema,R.,Constantinescu,G.,&Melville,B.W.(2017).Flow-field complexity and design estimation of pier-scour depth:Sixty years since laursen and toch.Journal of Hydraulic Engineering,143(9),03117006.
Ettema,R.,Melville,B.W.,&Constantinescu,G.(2011).Evaluation of bridge scour research:Pier scour processes and predictions:Washington,DC:Transportation Research Board of the National Academies.
Gobert,C.,Link,O.,Manhart,M.,&Zanke,U.(2010).Discussion of “coherent structures in the flow field around a circular cylinder with scour hole”by G.Kirkil,S.G.Constaninescu,and R.Ettema.Journal of Hydraulic Engineering,136(1),82-84.
Graf,W.H.,&Istiarto,I.(2002).Flow pattern in the scour hole around a cylinder.Journal of Hydraulic Research,40(1),13-20.
Hsieh,S.C.,Low,Y.M.,&Chiew,Y.M.(2016).Flow characteristics around a circular cylinder subjected to vortex-induced vibration near a plane boundary.Journal of Fluids and Structures,65,257-277.
Keshavarzi,A.,Melville,B.,&Ball,J.(2014).Three-dimensional analysis of coherent turbulent flow structure around a single circular bridge pier.Environmental Fluid Mechanics,14(4),821-847.
Kirkil,G.,&Constantinescu,G.(2010).Flow and turbulence structure around an instream rectangular cylinder with scour hole.Water Resources Research,46(11),W11549.
Kirkil,G.,Constantinescu,S.,&Ettema,R.(2008).Coherent structures in the flow field around a circular cylinder with scour hole.Journal of Hydraulic Engineering,134(5),572-587.
Link,O.,Gonzalez,C.,Maldonado,M.,&Escauriaza,C.(2012).Coherent structure dynamics and sediment particle motion around a cylindrical pier in developing scour holes.Acta Ceophysica,60(6),1689-1719.
Melville,B.W.,&Chiew,Y.M.(1999).Time scale for local scour at bridge piers.Journal of Hydraulic Engineering,125(1),59-65.
Melville,B.W.,&Coleman,S.E.(2000).Bridge scour.Highlands Ranch,CO,U.S.:Water Resources Publications.
Melville,B.W.,&Raudkivi,A.J.(1977).Flow characteristics in local scour at bridge piers.Journal of Hydraulic Research,15(4),373-380.
Paik,J.,Escauriaza,C.,&Sotiropoulos,F.(2007).On the bimodal dynamics of the turbulent horseshoe vortex system in a wing-body junction.Physics of Fluids,19(4),045107.
Raudkivi,A.J.(1998).Loose boundary hydraulics((4th ed.).Rotterdam,Netherland:Balkema.
Schanderl,W.,&Manhart,M.(2016).Reliability of wall shear stress estimations of the flow around a wall-mounted cylinder.Computers and Fluids,128,16-29.
Schanderl,W.,Jenssen,U.,Strobl,C.,&Manhart,M.(2017).The structure and budget of turbulent kinetic energy in front of a wall-mounted cylinder.Journal of Fluid Mechanics,827,285-321.
Sheppard,D.,Melville,B.W.,&Demir,H.(2014).Evaluation of existing equations for local scour at bridge piers.Journal of Hydraulic Engineering,140(1),14-23.
Soloff,S.M.,Adrian,R.J.,&Liu,Z.C.(1997).Distortion compensation for generalized stereoscopic particle image velocimetry.Measurement Science and Technology,8(12),1441.
Sumer,B.,&Fredsoe,J.(2001).Wave scour around a large vertical circular cylinder.Journal of Waterway,Port,Coastal,and Ocean Engineering,127(3),125-134.
Wei,M.,&Chiew,Y.M.(2018).Characteristics of propeller jet flow within developing scour holes around an open quay.Journal of Hydraulic Engineering,144(7),04018040.
Apsilidis,N.,Diplas,P.,Dancey,C.L,&Bouratsis,P.(2016).Effects of wall roughness on turbulent junction flow characteristics.Experiments in Fluids,57(1),12.
Bouratsis,P.,Diplas,P., Dancey,C.L,&Apsilidis,N.(2017).Quantitative spatiotemporal characterization of scour at the base of a cylinder.Water,9(3),227.
Chen,Q.,Qi,M.,Zhong,Q.,&Li,D.(2017).Experimental study on the multimodal dynamics of the turbulent horseshoe vortex system around a circular cylinder.Physics of Fluids,29(1),015106.
Cheng,N.S.,Chiew,Y.M.,&Chen,X.(2016).Scaling analysis of pier-scouring processes.Journal of Engineering Mechanics,142(8),06016005.
Chiew,Y.M.,&Melville,B.W.(1987).Local scour around bridge piers.Journal of Hydraulic Research,25(1),15-26.
Dargahi,B.(1987).Flow field and local scouring around a cylinder,137.Stockholm:Bulletin,Kungl Tekniska Hogskolan,Institution for Vattenbyggnad.
Dargahi,B.(1989).The turbulent flow field around a circular cylinder.Experiments in Fluids,8(1),1-12.
Dargahi,B.(1990).Controlling Mechanism of Local Scouring.Journal of Hydraulic Engineering,116(10),1197-1214.
Devenport,W.J.,&Simpson,R.L.(1990).Time-dependent and time-averaged turbulence structure near the nose of a wing-body junction.Journal of Fluid Mechanics,210, 23-55.
Dey,S.,&Raikar,R.(2007).Characteristics of horseshoe vortex in developing scour holes at piers.Journal of Hydraulic Engineering,133(4),399-413.
Ettema,R.,Constantinescu,G.,&Melville,B.W.(2017).Flow-field complexity and design estimation of pier-scour depth:Sixty years since laursen and toch.Journal of Hydraulic Engineering,143(9),03117006.
Ettema,R.,Melville,B.W.,&Constantinescu,G.(2011).Evaluation of bridge scour research:Pier scour processes and predictions:Washington,DC:Transportation Research Board of the National Academies.
Gobert,C.,Link,O.,Manhart,M.,&Zanke,U.(2010).Discussion of “coherent structures in the flow field around a circular cylinder with scour hole”by G.Kirkil,S.G.Constaninescu,and R.Ettema.Journal of Hydraulic Engineering,136(1),82-84.
Graf,W.H.,&Istiarto,I.(2002).Flow pattern in the scour hole around a cylinder.Journal of Hydraulic Research,40(1),13-20.
Hsieh,S.C.,Low,Y.M.,&Chiew,Y.M.(2016).Flow characteristics around a circular cylinder subjected to vortex-induced vibration near a plane boundary.Journal of Fluids and Structures,65,257-277.
Keshavarzi,A.,Melville,B.,&Ball,J.(2014).Three-dimensional analysis of coherent turbulent flow structure around a single circular bridge pier.Environmental Fluid Mechanics,14(4),821-847.
Kirkil,G.,&Constantinescu,G.(2010).Flow and turbulence structure around an instream rectangular cylinder with scour hole.Water Resources Research,46(11),W11549.
Kirkil,G.,Constantinescu,S.,&Ettema,R.(2008).Coherent structures in the flow field around a circular cylinder with scour hole.Journal of Hydraulic Engineering,134(5),572-587.
Link,O.,Gonzalez,C.,Maldonado,M.,&Escauriaza,C.(2012).Coherent structure dynamics and sediment particle motion around a cylindrical pier in developing scour holes.Acta Ceophysica,60(6),1689-1719.
Melville,B.W.,&Chiew,Y.M.(1999).Time scale for local scour at bridge piers.Journal of Hydraulic Engineering,125(1),59-65.
Melville,B.W.,&Coleman,S.E.(2000).Bridge scour.Highlands Ranch,CO,U.S.:Water Resources Publications.
Melville,B.W.,&Raudkivi,A.J.(1977).Flow characteristics in local scour at bridge piers.Journal of Hydraulic Research,15(4),373-380.
Paik,J.,Escauriaza,C.,&Sotiropoulos,F.(2007).On the bimodal dynamics of the turbulent horseshoe vortex system in a wing-body junction.Physics of Fluids,19(4),045107.
Raudkivi,A.J.(1998).Loose boundary hydraulics((4th ed.).Rotterdam,Netherland:Balkema.
Schanderl,W.,&Manhart,M.(2016).Reliability of wall shear stress estimations of the flow around a wall-mounted cylinder.Computers and Fluids,128,16-29.
Schanderl,W.,Jenssen,U.,Strobl,C.,&Manhart,M.(2017).The structure and budget of turbulent kinetic energy in front of a wall-mounted cylinder.Journal of Fluid Mechanics,827,285-321.
Sheppard,D.,Melville,B.W.,&Demir,H.(2014).Evaluation of existing equations for local scour at bridge piers.Journal of Hydraulic Engineering,140(1),14-23.
Soloff,S.M.,Adrian,R.J.,&Liu,Z.C.(1997).Distortion compensation for generalized stereoscopic particle image velocimetry.Measurement Science and Technology,8(12),1441.
Sumer,B.,&Fredsoe,J.(2001).Wave scour around a large vertical circular cylinder.Journal of Waterway,Port,Coastal,and Ocean Engineering,127(3),125-134.
Wei,M.,&Chiew,Y.M.(2018).Characteristics of propeller jet flow within developing scour holes around an open quay.Journal of Hydraulic Engineering,144(7),04018040.