Author(s): Shehua Huang; Liuyan Hu; Qiang Zeng
Linked Author(s):
Keywords: Surface flow pattern of confluent meandering bend; Longitudinal and lateral slope; Separation region; Flux ratio
Abstract: This paper has shown experimental results of averaged turbulent flow pattern and 3D water surface configuration in confluent bend channel. The experiments are performed in a conceptual physical model of 180° main bend channel with a straight tributary intersecting at the bend apex of concave bank. Flow velocities on water surface of confluence bend are measured by means of three-dimensional acoustics doppler velocimeter (ADV). The elevations of free water surface are also obtained by ADV technology. The main achievements of experiment are as follows. Since tributary enters into the bend flow, water surface of upstream before interaction position becomes flat, and at downstream the water surface slope gets much large. In interacting section of bend flow, lateral water surface slope varies from positive to negative as radial coordinate increases, which means that the largest water level in the same cross section is located in the middle of channel rather than in outer bank. The longitudinal hydraulic slope also gets its largest value in the interacting section of confluent flow. The results of flow velocity vector on free water surface are obtained for various flux ratio. When flux ratio is large, obvious flow separation occurs downstream near out bank.
Year: 2013