水科学进展2012，Vol.23Issue(3)：369-375,7.
明渠弯道水流平均运动规律试验研究
Experimental study of open channel flow in a bend
摘要
Abstract
Measurement of open-channel-flow in a bend was made by using particle image velocimetry to get instantaneous two-dimensional velocity data based on which the mean, three-dimensional flow fields were reconstructed. The results show the main flow deviates to the convex bank upon entering the bend, then quickly shifts to the concave bank due to centrifugal force and remains near the concave bank until the end of the bend. Velocity gradient near the bed and location of the maximum velocity of the streamwise mean velocity profiles at each transverse location keep changing along the bend due to the action of concave bank lockup and secondary flow. Distance between bend entrance and the section in which the maximum depth-averaged streamwise velocity approach the concave bank increases with the curvature of the bend flume. There exist three-vortex structure in each section near the bend entrance affected by the secondary flow in the upstream straight flume, but this quickly decay into two-vortex structures in other sections. Both the strength of the major secondary flow and the location of its core changes along the bend.关键词
明渠弯道/粒子图像测速/流速剖面/环流运动/涡结构/弯道曲率Key words
open channel bend/ particle image velocimetry/ velocity profile/ secondary flow/ vortex structure/ bend curvature分类
建筑与水利引用本文复制引用
陈启刚,钟强,李丹勋,王兴奎..明渠弯道水流平均运动规律试验研究[J].水科学进展,2012,23(3):369-375,7.基金项目
国家自然科学基金资助项目(50779023) （50779023）
