Bend Flow Under The Conditions Of Curve Intersection Study On Hydraulic Characteristics Of The Curve

Tributary miter mainstream is a natural phenomenon widespread in natural river. Because natural river have a varies of morphology,according to the morphological characteristics of the intersection near the entrance of the main stream which can be divided into the curved and straight intersection of two major types. Curved river flow regime itself is very complex, so that the curve tributary confluence of local geometry and hydraulic conditions are more complicated, showing a lot of water dynamics:tributary has influence on the upper reaches of the water, because of backwater effect,the characteristic of the separation zone in downstream of the confluence,high and low velocity zone. These characteristics influenced by many factors, including the shape of the junction, riverbed elevation of main stream and tributaries, channel gradient(slope), the size of the angle of convergence, ratio of discharge. Among them the ratio of discharge and the junction angle are important factors influenced on hydraulic characteristics. Therefore, the study of flow characteristics at the confluence curved corners not only has important theoretical value, but also has a positive practical value in shipping, design of hydraulic structures, river training and so on.The subject in view of the which tributaries intersection in the convex bank test, study the ratio of discharge and the junction angle are effected on bend of flow characteristics near by junction. In previous studies mainly investigated hydraulic characteristics of tributaries converge the main stream in a straight line, but relatively few studies tributary skew curve river. Compare tributaries intersection in the convex bank and tributaries intersection in the concave bank, tributaries flow into the main stream of the corners due to the influence of centrifugal force, backwater effect of tributaries to the mainstream will become more apparent,resulting in river flow field dramatic changes in the distribution,causing major swings, disturb sediment transport, affect the main city river water greatly, sediment movement conditions on channel conditions will also cause great interference. Therefore, develop research about the flow characteristics of tributary converge on convex bank bend has a great significance on the analysis of the evolution of river, river improvement measures of the development.On the basis of this study abroad confluence river flow characteristics analysis and research, on the design and establishment of a generalized physical model test, conducted water test, used Doppler velocity meter(ADV) and other instruments to analyze the angel of convergence,ratio of discharge have effect on junction and its downstream vicinity surface water movement,hydraulic gradient changes, changes in flow rate characteristic and circulation strength,reach the intersection of the flow velocity distribution and the distribution of power flow axis. Research results show that, when inflow angle is larger,effect of tributaries on the mainstream is getting stronger; vertical average velocity reaches the peak at the concave bank in downstream section. With the increase of inflow angle of the overall,there becomes an uneven distribution of flow velocity. When inflow angle becomes larger, the rotation intensity of the concave side is less than the convex bank of the first half segment, circulation intensity becomes stronger and stronger and the sections with the largest circulation intensity at the concave bank in downstream section is moving downward gradually; the highest point of the axis of power has moved to the left bank of the trend and closer to the confluence of the swing more violently; the curve concave vertical slope with shore water bus ratio increases in the confluence section of the surface elevation changes along the greater; water level in the transverse direction changed in a curve, with the ratio of discharge is decreased, the slope Jc of main stream,became more and more increased.The topic for different junction angle and ratio of discharge of the curved corners confluence hydraulic characteristics of in-depth system analysis, intended for such junction corners of further scientific research, project designed to study river regulation and other characteristics of the reference.