The Hydraulic Characteristic Study On Hydraulic Automatic Rolling Gate

In northwestward of our country, there are numerous small and medium rivers. Moreover, sediment content in rivers is very high. The common gate is easily to encounter with blocking sediment. Rolling gates, as a kind of hydraulic automatic gate, has some advantages of simple structure, reliable operation and no external power, is suitable for operating in rivers with higher percent sand, realizes the characteristic of free operation in rivers with sediment accumulation, and is extremely fit for constructing in small rivers in unwatered northwest. Therefore, studying hydraulic characteristic of hydraulic self-control gates has the beneficial theoretical basis on designing small hydro-junction and operating management.By using the method of combining with model test and numerical modeling, the paper studies pressure distribution characteristics of flow capacity of rolling gate with gatage, diameter principle of cylinder and surface cylinder in different depth. The following research results are obtained:(1) When roller surface overflows and opening gate doesn’t overflow, overflowing flow will increase with depth and presents variation tendency of function curve. Moreover, slope of a curve is increased with the increase of water depth(2) When opening roller is a certain, flow capacity is increased with water depth before gate and presents increasing tendency of power function. When flow stays in outflowing, slope of a curve is reduced with the increase of water depth. When flow stays at weir flow stage, slope of a curve is increased with the increase of water depth.(3) The paper derives flow calculation formula of overflowing roller surface and outflowing opening gate, and gives flow calculation formula under the condition of surface overflow and outflow of opening gate on the basis of it, and measures critical flow of rolling roller.(4) It uses experimental method and numerical modeling to obtain pressure profile of surface roller.