摘要
利用粒子图像测速技术(PIV)实现了基于涡量的剪切层和分离区位置的精确确定,同时对汇流区水平面内的涡旋结构进行系统观测和分析。研究发现:剪切层和分离区近水面和近底面水深平面的涡旋密度大,水深中部的涡旋密度小;支流流量增大的情况下涡旋密度均增大。槽底壁面湍流是近底面涡旋密度大的主要原因。剪切层由水流剪切产生的剪切涡以小旋转强度涡旋为主,分离区由水流分离产生的分离涡以中等及小旋转强度涡旋为主。
Particle image velocimetry (PIV) technique is used to accurately determine the location of shear layer and separation zone based on vorticity.Meanwhile,the vortices in the horizontal plane at the confluence are systematically observed and analyzed.It is found that the vortex density within both the shear layer and the separation zone is larger near the water surface and near the bottom than that in the middle of water depth.The vortex density increases with the increase of tributary discharge when the discharge of main channel is fixed.The high density of vortices near the bottom is caused by the wall turbulence.In addition,the shear layer generated by flow shear is dominated by vortices with small swirling strength,while the separation zone generated by the flow separation is dominated by vortices with medium and small swirling strength.
作者
林青炜
唐洪武
袁赛瑜
陈康
肖洋
LIN Qingwei;TANG Hongwu;YUAN Saiyu;CHEN Kang;XIAO Yang(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University,Nanjing 210098,China;College of Water Conservancy and Hydropower Engineering, Hohai University,Nanjing 210098,China)
出处
《河海大学学报（自然科学版）》
CAS
CSCD
北大核心
2019年第4期352-358,共7页
Journal of Hohai University(Natural Sciences)
基金
江苏省研究生科研与实践创新计划(KYCX18_0599)
中央高校基本科研业务费专项(2018B629X14)
国家自然科学基金(51779080)
关键词
粒子图像测速技术
河道水流交汇区
剪切层
分离区
涡旋
涡量
旋转强度
水槽试验
particle image velocimetry
river confluence
shear layer
separation zone
vortex
vorticity
swirling strength
flume experiment
