Circulation characteristics of horseshoe vortex in scour region around circular piers

作     者：Subhasish DAS Rajib DAS Asis MAZUMDAR 

作者机构：School of Water Resources EngineeringJadavpur University 

出 版 物：《Water Science and Engineering》 (水科学与水工程（英文版）)

年 卷 期：2013年第6卷第1期

页      面：59-77页

核心收录：

学科分类：080103[工学-流体力学] 08[工学] 080104[工学-工程力学] 081502[工学-水力学及河流动力学] 0815[工学-水利工程] 0801[工学-力学（可授工学、理学学位）] 

基　　金：The helpful suggestions from Professor (Dr.) Subhasish Dey  Brahmaputra Chair Professor for Water Resources of the Department of Civil Engineering  at the Indian Institute of Technology in Kharagpur  India are gratefully acknowledged. The authors also appreciate the help provided by Mr. Ranajit Midya and Mr. Ranadeep Ghosh  M.E. students of the School of Water Resources and Engineering  at Jadavpur University in Kolkata  India  during the investigation 

主　　题：experimental investigation," open channel turbulent flow," scour," horseshoe vortex,"circulation," circular pier forward difference technique," Stokes theorem 

摘      要：This paper presents an experimental investigation of the circulation of the horseshoe vortex system within the equilibrium scour hole at a circular pier, with the data measured by an acoustic Doppler velocimeter （ADV）. Velocity vector plots and vorticity contours of the flow field on the upstream plane of symmetry （y = 0 cm） and on the planes ：e3 cm away from the plane of symmetry Cv = ~3 cm） are presented. The vorticity and circulation of the horseshoe vortices were determined using the forward difference technique and Stokes theorem, respectively. The results show that the magnitudes of circulations are similar on the planes y = 3 cm and y = -3 cm, which are less than those on the plane y = 0 cm. The circulation decreases with the increase of flow shallowness, and increases with the densimetric Froude number. It also increases with the pier Reynolds number at a constant densimetric Froude number, or at a constant flow shallowness. The relative vortex strength （dimensionless circulation） decreases with the increase of the pier Reynolds number. Some empirical equations are proposed based on the results. The predicted circulation values with these equations match the measured data, which indicates that these equations can be used to estimate the circulation in future studies.