Alluvial channel hydrodynamics around tandem piers with downward seepage

作     者：Rutuja CHAVAN Wenxin HUAI Bimlesh KUMARC Rutuja CHAVAN;Wenxin HUAI;Bimlesh KUMAR

作者机构：Department of Civil EngineeringMaulana Azad National Institute of Technology BhopalBhopalMadhya Pradesh 462003India Department of HarborSchool of Water Resources and Hydropower EngineeringWuhan UniversityWuhan 430072China Department of Civil EngineeringIndian Institute of Technology GuwahatiGuwahati 781039India 

出 版 物：《Frontiers of Structural and Civil Engineering》 (结构与土木工程前沿（英文版）)

年 卷 期：2020年第14卷第6期

页      面：1445-1461页

核心收录：

学科分类：1305[艺术学-设计学（可授艺术学、工学学位）] 08[工学] 0813[工学-建筑学] 0814[工学-土木工程] 080101[工学-一般力学与力学基础] 0801[工学-力学（可授工学、理学学位）] 

主　　题：scour seepage Strouhal number tandem arrangement turbulent characteristics 

摘      要：In this paper,we report the turbulent flow structures and the scour geometry around two piers with different diameters.An experiment was conducted on a non-uniform sand bed with two types of tandem arrangements,namely,pier(T1)with a 75 mm front and 90 mm rear,and pier(T2)with a 90 mm front and 75 mm rear,with and without-seepage flows,respectively.A strong wake region was observed behind the piers,but the vortex strength diminished with downward seepage.Streamwise velocity was found to be maximum near the bed downstream of the piers and at the edge of the scour hole upstream of the piers.Quadrant analysis was used to recognize the susceptible region for sediment entrainment and deposition.Upstream of the piers near the bed,the moments,turbulent kinetic energy(TKE),and TKE fluxes were found to decrease with downward seepage,in contrast to those in a plane mobile bed without piers.The reduction percentages of scour depth at the rear pier compared with the front one were approximately 40%for T1 and 60%for T2.Downward seepage also resulted in restrained growth of scouring with time.