Influence Of Section Structural Characteristics Of Labyrinth Channels On The Hydraulic Performance Of Emitters

China is one of the poorest countries in per capita water resources with backward irrigation technology.With the rapid development of economic growth and society, the shortage of water resources not only limit the exploiting of land resources, but also hinder the development of economic growth and society. The National Eleventh Five Year Plan has focused on rural irrigation and its main concern are rural water conservancy and to promote the using of water-saving irrigation technology.As a kind of high efficiency and effective water-saving irrigation method drip irrigation has attracted wide public concern all over the world. Because of the late beginning and rapid progress of drip irrigation, construction parameters are short of reference frame in channel design. The majority of micro irrigation products have many problems, such as the long-term research and development, the high cost, backward fabricate technology, poor anti-chock capability and so on.In order to solve these problems, the key problem is to improve the hydraulic performance of emitters. Using software Fluent 6.1,section shapes (wetted perimeter)and section areas of labyrinth channels can be used as control parameters to describe section structure characteristics to conduct numerical simulation of fluid in labyrinth channels. The research analsizes the influence of section structure characteristics of labyrinth channels on the hydraulic performance of emitters and draw a conclusion.1)The results show positive relationship between wetted perimeter and discharge coefficient and flow state exponent. With the increase of wetted perimeter of labyrinth channels section, pressure change sensitivity of the emitters increases. Because of the reynolds number decreased, it is unease to form turbulent flow.The main velocity regions became wider and the areas of high velocity regions become wider and will cause vortexs at the angle of medial labyrinth channel. There exist low velocity regions and the lateral body of labyrinth channel becomes wider. It is easy to deposit and leads to the clogging of drip irrigation emitter. Therefore, the longer the length of wetted perimeter is, the worse the hydraulic performance of emitters, it's capability in disappear energy and jam-resisting capability.2)The results show positive relationship between section areas of labyrinth channels and discharge coefficient. There was a negative correlation between section areas and flow state exponent. With the increasing of the section areas of labyrinth channels section, pressure change sensitivity of the emitters is increasing. While the Reynolds number increases, it is easier to form turbulent flow. Main velocity regions and high velocity regions become wider. Low velocity regions become narrower. The results showed that with the increase of section areas, the hydraulic performance, capability in disappear energy and jam-resisting capability of emitters can be improved.3) The square section is a special form of rectangle section of labyrinth channels. When labyrinth channels sections have the same areas, the square section of labyrinth channels can decrease pressure change sensitivity of the emitters, discharge coefficient and flow state exponent of labyrinth channels become smaller. Main velocity regions and high velocity regions become wider, while low velocity regions become narrower. The results showed that the hydraulic performance, capability in disappear energy and jam-resisting capability of the square section of labyrinth channels emitters are better than rectangle section of labyrinth channels emitters.