Experiments Study On The Structure For Ice-covered River Flow

The presence of ice in river is an important phenomenon to be considered in the development of water resources in cold regions. Rivers in cold areas usually form ice cover during winters, which involve many processes which are affected by the ambient meteorological and hydrological conditions and interact in a complex manner with the river flow. The traditional open channel has turned into covered one by the forming of the ice cover, which always changes the conditions of flowing, heat and geometry profiles of the river. When it becomes serious , it will lead to ice flood disasters. The structure of ice cover river flow is different from open channel flow's, because the ice cover river flow suffer the wall resistance and the ice cover resistance's dual influences. The current structure problem is often encountered and necessary to study and solve such as hydropower plant in water conservancy project in cold regions, but also the foundation of studying in underwater ice's formation and evolution. Because of the ice evolution closely related to the flow condition in the channels, the study on its current structure is also extremely important to the long-distance water supplying safety. And this has an important practical significance on avoiding the occurrence of disasters, reducing the threat of ice flood.The structure of ice cover river flow has been analytical studied, which based on prototype observation, interior model experiment and theoretical analysis. This paper consists of three aspects:Firstly, in the paper, the author analyzed and systematically summarized the study current situation of ice at home and abroad on the basis of the evolution of river ice and the type of ice harm. Secondly, according to the previous research results with experimental data, the author made a comprehensive analysis of the velocity distribution of continuous, discontinuous and shore ice cover flow, compared with the water distribution ability of the ice cover flow and open channel with the same depth, and fitted the water capacity equation of ice cover flow. Thirdly, the writer summarized the research on ice-cover roughness and comprehensive roughness and got together various roughness formulas. Compared with test results, the results show that Sabaneev formula more general and accurate, and prove feasibility that logarithm assumption in the study roughness of ice cover. In this paper, take two-dimensional turbulent flow for example, Einstein assumption applied on ice-cover flow was theoretically analyzed while it using in the ice-cover river study. The result shows that the assumption is not fit to all ice-cover flows, and the author give the applicable conditions in engineering application and mathematical model.