The Study On The Flow Characteristics Around Spur Dikes Of Different Structures

Spur dike is a kind of main regulation structure that is widely used in channel regulation engineering for controlling the shape of the nature river. Some complex flow characteristics such as flow separation, circumfluence appears around spur dikes. It is of great importance for the design of channel regulation structure to explore the effect of spur dikes on flow, and to study the flow structure. The work in the thesis is studied combining with the research project-key scientific and technical project on west China transportation.In this thesis, we make a brief review and comment for the existing research on the the flow structure near spur dike Combined with results of previous studies, This subject relying on the channel construction projects in the Xuyu reach of upper reaches of the Yangtze River, survey statistical analysisi the damage situation of the rapids remediation buildings。 Make five kinds of different structural forms of spur dike, respectively conduct test of water scour on fixed bed。 The test use "DCMS flow rate system" to control the flow, use "ADV three dimensional flow rate measuring instrument" to collect the data。Through the flume experiments, combined with theoretical analysis.Studied the water’s surface line、flow rate、cross section ratio and turbulent features that near the spur dike of different flow conditions and different types of spur dike.Drawn out the contour map that about the water’s surface line、flow rate、cross section ratio and turbulent features that near the spur dike of different flow conditions and different types of spur dike. Details the differents between the turbulence intensity distribution of the five types of dam structure. The innovative achievements mainly are:(1) putting forward by using groin structural form about transerse section of circular arc, test results show that its damaded level is smaller than the structural form of trapezoidal cross-section in the same water-sandiment conditions.(2)firstly full reveals the3D turbulence intensity and kinetic energy distribution around five different structure forms of the groin, this paper expounds the difference of turbulence situation around the dam between different type.