摘要
四面六边透水框架是一种新型的防冲促淤结构,一般是由6根相同的杆件相互搭接而成的透空正四面体.采用平面二维粒子图像测速仪(PIV)对四面六边透水框架"迎流布置"和"背流布置"两种典型布置方式下的框架周边流场分别进行了测量,采用240个瞬时流场计算得到了水流时均和紊动流场特性,并与无框架作用下的流场进行了对比.结果表明,框架的存在对水流产生了较大干扰,水流结构发生明显改变;通过分析典型截面上框架后方的流速、紊动强度、雷诺应力及总切应力垂向分布和减速率,揭示了透水框架的防冲促淤机理,并对比了两种布置形式的减速效果,认为背流布置比迎流布置减速效果更好.
The tetrahedron-penetrating frame, which is typically composed of six member bars with the same size and style, has been widely used in river engineering as a new effective scour countermeasure structure. A 2D particle image velocimetry （PIV）technology was used to measure the flow field around the tetrahedron frame under two arrangements （i. e. , frame vertex pointing upstream and downstream ）. The time-averaged and turbulent flow statistics were obtained from 240 instantaneous flow fields, which were also compared with flow fields without any frames. The results indicate that the tetrahedron frame has an obvious perturbation effect on the flow field around it, thus changing the flow structure significantly. The vertical profile of the velocity, turbulent intensity, Reynolds stress, total shear stress, and decelerating rate of these two different arrangements are analyzed to explain the mechanism of the frame in retarding flow and inducing sediment deposition in sediment laden flows. In addition, comparisons of these arrangements indicate that frame vertex pointing downstream type works more efficiently in retarding flow.
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2014年第5期877-886,共10页
Journal of Basic Science and Engineering
基金
国家自然科学基金(51079105
51379157)
水体污染控制与治理国家科技重大专项子题(2012ZX07205-005-03)
关键词
四面六边透水框架
PIV
流速分布
减速率
紊动强度
雷诺应力
tetrahedron frame
PIV
velocity distribution
decelerate rate
turbulence intensity
Reynolds stress
