Mathematical Model Study On Flow Conditions Of Approach Channel Of Non-gate Low Dam

In recent years, in order to solve the problem of sediment, water for irrigation andnavigation conditions, more non-gate low dams been built. Non-gate low dam can raisethe water level of the upstream and impound sediment. Its main characteristic is that theheight of the dam is low and its spillway has no gate. So the water can flow through thedam freely. Those characteristics make the flow conditions of its approach channel verycomplex. So it is necessary to analyze the causes of complex flow conditions and studyon the improvement measures.This paper systematically summarizes the improvement measures of approachchannel and the mathematical model development. According to the date of the FujianMinjiang Shuikou hydropower station downstream water level control project and theresults of physical model, this paper establishes the average water depth of the finiteelement method of two-dimensional flow mathematical model. This model can simulatethe complex boundary conditions very well. It is good enough to use this model toresearch the improvement measures of approach channel.The conclusions are as follows:①After the comparison the results of mathematical model and physical model, theresult show that mathematical model are close to the physical model. It suggests that themathematical model and numerical methods are reasonable. This method can correctlysimulate water flow of approach channel.②Against the problem of the transverse velocity of approach entrance area is toobig, the measure of navigation jetty with holes been put forward. It can better simulatethe improvement of navigation jetty with holes.③According to the analysis of the upstream of Fujian Minjiang Shuikouhydropower station downstream water level control project, this paper concludes thecauses complex the flow conditions of approach channel.④After the mathematical simulation of multi-program improvement measures putforward to extend the navigation jetty, add navigation jetty with different sizes of holesand add the navigation pier. It makes the maximum navigation flow rate raised to12000m3/s.