The Study On The Hydraulic Characteristics Of Ecological Base Flow And Irrigation Drainage Holes

At present, the main way to use water resources is to build a variety of hydraulic structures in the river, But at the same time, it also makes the downstream river flow to reduce, causing the fish and other biological reduction in the river and ecological deterioration. Along with the enhancement of people's consciousness of ecological civilization, people realize the importance of protecting the ecological environment of the river. And keeping the river ecological health must maintain the base flow in the river, so the river ecological base flow has become a hot topic at present. China is still a big agricultural country, and it is very important to ensure the irrigation water to promote the development of agriculture. So when planning the construction of water conservancy project, we must take into account the agricultural irrigation water. Ecological base flow and irrigation drainage holes to meet the ecological basic flow and agricultural irrigation water. Ecological base flow and irrigation drainage hole protect the downstream ecological environment and ensure the agricultural water, but also reduce the amount of engineering, cost savings. Based on an ecological protection project, this paper uses the physical model test and numerical simulation to study the hydraulic characteristics of the ecological base flow and irrigation drainage holes. The main work of this paper is as follows:1. The report firstly outlined research significance and present situation of ecological base flow and irrigation drainage holes; Summarize the common sluice structure and energy dissipation method. The hydraulic characteristics of stepped spillway are introduced.2. Based on a practical ecological protection project, a physical model test was carried out on the ecological base flow and irrigation drainage holes. Under different working conditions, study water supply capacity of the ecological base flow and irrigation drainage holes and measure hydraulic elements of the corresponding values. Through analyzing the test result, we can get time averaged pressure and flow velocity distribution along the surface of the water of the ecological base flow and irrigation drainage holes. And we study energy dissipation of stilling basin and ladder the cavitation conditions.3. Because the energy dissipation of stilling basin is not enough Under the opening all sluice gate of the ecological base flow and the irrigation, In the middle of the energy dissipation basin to increase a wall of energy dissipation. Through the comparison and analysis of the hydraulic parameters of flow pattern and flow velocity, pressure and so on that prove that the scheme optimization played a significant effect. This scheme not only improves the efficiency of energy dissipation, still in stilling basin formed a good flow pattern.4. The basic theory of turbulence numerical simulation method, free surface model and numerical simulation method are introduced.5. Using CAD, ICEM and FLUENT to establish the three-dimensional numerical calculation model of the ecological base flow and irrigation drainage holes. Through numerical calculation, the flow field distribution of the whole ecological base flow and irrigation drainage hole is obtained, and the results of numerical simulation and physical model test results are compared and analyzed. The results prove that FLUENT numerical calculation software can simulate the turbulent flow of the ecological base flow and irrigation drainage holes and it can be used as a research method used in practical engineering.6. Through the physical model test and numerical simulation results, it is found that although the overall numerical agreement is good, but there are some errors, the analysis of the possible causes of error.