| Irrigation of economizing on water is an important part of modernizing agriculture, it is the only way to realize modernization that it develops irrigation of economizing on water and improves utilization ratio of water. Today my country's conditions are: on the one hand the natural resources of water is seriously inadequate, on the other hand it is the very low utilization ratio of agricultural irrigated water and is seriously wasted. Agriculture irrigation of my county has been continued to use old methods for a long period of time, so it has large space of economizing on water.Irrigation of economizing on water is the floorboard which adopts multi-measures according to the rules that crops need water and the local conditions that supply water. These measures could effectively make use of precipitation and irrigated water, meanwhile obtain most beautiful economic benefits, social benefits and environmental benefits. From headwaters to field irrigated water would go through several segments, every segment has useless losses of water . In these segments all sorts of measure that could decrease the losses of water and improve the efficiency of using water an economic benefits belong to the category of irrigation of economizing on water.There are mainly below kinds about the measures of irrigation of economizing on water .(1) Reasonably developing and using the natural resources of water.(2) Reducing losses of water in irrigation ditch.(3) Adopting methods and techniques of irrigation of economizing on water. (4)Techniques of economizing on water in agriculture namely finding methods ofeconomizing on water from crops themselves.(5) Improving management level of using water.Technique of sprinkle irrigation is one of methods of economizing on water. It is a method that makes pressure water carried into irrigated land and sprinkled into air to form water drips through sprinkler then sprinkled on crops and fields like raining. The pressure water is formed to make water raised pressure by special equipments or to utilize the natural drop in level of water. Sprinkle irrigation not only could satisfy with maintained needs of garden an playground lawn but also add a beautiful landscape for people's living environment. This method has many advantages such as saving water, increasing output, saving labor and land, protecting soil and fertilizer, strong adaptability, using synthetically and so on.There are some equipments of sprinkle irrigation in common use in techniques of sprinkle irrigation. They are electric circular sprinkle irrigation machine, electric parallel sprinkle irrigation machine, rolling sprinkle irrigation machine and hard hose traveler. Hard hose traveler is mainly researched in this text.Basing on sprinkle irrigation system of moving pipe hard hose traveler is developed in the early of 1970s. It is a sprinkle irrigation machines and tools which has compact structure, convenient movement, few operation staff and automatic walking to sprinkle. Hard hose traveler is composed of sprinkler, flexible tubing, waterpower driver, coiling-plate vehicle and so on. When it is used to irrigate, the flexible tubing is dragged and paved on the irrigated land, the coiling-plate is revolved and the flexible tubing is coiled through driving the coiling-plate taking advantage of pressure water, the sprinkler is towed and moves slowly to the coiling-plate to spray. In these components, the flexible tubing is black medium-density polyethylene semi-hose. This hose has many advantages such as bearing high pressure, bearing traction and dragging, bearing bends. Its using life may reach over ten years. Operation is handy. It can run automatically and only need one or two persons to manage. It can word day and night, only need one or two times to move every day, merely need twenty minutes to install. Each machine can control the land area of 3~50hm2 and fit different regions, crops and water. The irrigated area needs not every engineering facilities, nor is influenced of barriers such as trees, telephones pole and so on. Only does water exist, with giving pressure water, it can move to sprinkle and irrigate. After accomplishment it may make the whole machine delivered into warehouse and taken care. According to these advantages, it is necessary to design hard hose traveler.The first step of designing hard hose traveler is to choose the diameter reel of coiling-plate in the system of carrying water. When pressure loss in coiling hoses is small an steady, the diameter is right. Through understanding some basic knowledge of fluid-mechanics, we know, under the condition of giving the coefficient, the fluid in coiling hoses namely water is sticky, not compressive turbulent. There are two kinds of pressure losses in coiling hoses. One is pressure loss along the route of travel. Another is parts of pressure loss. The causes leading to the first kind of pressure loss are mainly the internal friction between layers of fluid along the route of travel. While the second is mainly caused by hoses' bends. When the flow passes the bend hoses, direction of fluid is restrained an sets up secondary or double spiral flow. So the water can not develop folly and energy of the mainflow is exhausted.In order to define the best ratio of the bend radius , it is necessary to experiment and study for pressure loss of hoses. It is realized through adopting to the combine of computer imitation and practical experiment in this text.In computer imitation experiment, we use computer software of FLUENT to analyze the flow of hoses. FLUENT is program to compute the question about fluid and transmitting heat. This program consists of five sections. The first is GAMBIT to build geometric form and generate mesh. The second is FLUENT to imitate and compute flow. The third is prePDF to imitate the burning process of PDF. The fourth is TGRID to generate voiume mesh from the existing border mesh. The last is Filters(Translators) to transform the mesh which is formed with other programs. The former two parts are involved in flow imitation of the coiling hoses. Because it is very difficult to draw bend hose in GAMBIT, the 1/4 bend hose of this experiment is designed in AutoCAD with applying special program. Then it is imported to GAMBIT. After importing it, the model is meshed and the boundary type is defined in GAMBIT. Meanwhile the mesh is exported for FLUENT 5/6. Opening FLUENT, the mesh file is read. After checking mesh, forming the model of computing, setting up the standard turbulent model, controlling the compute, the computing starts. Finally the imitating experiment datum of 1/4 bend hose of different ratio of bend radius are achieved.In the practical experiment, we build a test installation according to the flow chart. The used materials are water pump, glass rotor of flow gauge, valves, pressure gauge, iron pipe and so on. Regulating valves' angle and making the valve of flow gauge controlled 5 m3/h, in this time we write the reading of pressure gauge and change the pipe of experiment. Finally we achieve the values of pressure losses which coil on hard hose traveler with one circle and the ratios of bend radius are differently 215 millimeters, 315 millimeters, 415 millimeters and 515 millimeters.After analyzing the datum of imitation experiment and practical experiment, it can conclude that the datum of two ways are identical in the main and the ratio of error is under two percent. So it can use the datum of imitation experiment to take the place of practical experiment. Some datum that is difficult to determine by practical experiment become possible. It improves the accuracy of experiment. The datum of imitation experiment are drawed into curve. By analyzing the curve, the best ratio of bend radius is 415 millimeters. In other words it is most suitable that the diameter of coiling-plate is 800 millimeters.
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