Resrarch Of Pressure Losses From Hose Coiling On Hard Hose Travelers

This research is based on a solar-powered hard hose traveler which is developed by Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling, Shaanxi Province, China. In order to analyze the pressure loss from hose coiling on hard-hose travelers and explores the pressure loss from hose coiling of different flow patterns, a pressure loss test platform was built, while characteristics of the pressure loss from hose coiling on hard-hose travelers in the process of hose roll up being analyzed at the same time. Some experiment have done to test the pressure loss from hose coiling on hard-hose travelers layer by layer and single-turn by single-turn in different working conditions(stationary state and the actual working state),as well as the pressure loss of the same and different layer from hose coiling on hard-hose travelers in different working conditions. concurrently experiment have done to test hard hose travelers when they are working in the open field. According to the above results of the experiment and simulation, the main results were as follows.(1)According to the results of contrast analyses of the pressure loss between the straight hose and coiled hose, pressure loss from coiled hose is larger than straight hoses, when flow velocity is same in the hose; with the increase of the flow velocity, the difference of pressure losses will increase. The pressure loss of coiled hose is mainly caused by the whirlpool loss on the outside of water flow and secondary flow by the centrifugal force. Reel diameter of axle is 1.28 m, 27.2 < r < 53.6 mm, in the same flow velocity condition, pressure loss from coiled hose decrease with increasing of r.(2)According to test results of pressure losses of single-turn volume hose, when Reynolds number between 29630 and 159208, 27.2< r <53.6mm,0.16<Δ/0d <0.55, which the flow patterns were turbulent regionⅠand turbulent region Ⅱ area, there was a relationship between pressure loss of coiled hose and flow patterns. Simultaneously, hose pressure loss coefficient and pressure loss formula were presented, whice provided a reference for calculating water inlet pressure of hard-hose travelers.(3)Some experimental projects were simulated by CFD software in this paper, while the turbulence models were standard model-ke and Realizable-ke whice are commonly used in engineering. By comparing simulation results with experimental results, it find that turbulence model Realizable-ke can more accurately simulate the pressure loss of coiled hose.(4)When hard hose travelers are in different working conditions, while the testing factors of the coiled hoses are the same, the pressure losse of coiled hose is almost the same.(5)When hard hose travelers are in different working conditions, while the testing factors of different layers coiled hoses are the same, the pressure losse of coiled hose is different. When the condition is working state, the pressure loss of other layer coiled hose can get get by multiplying the corresponding coefficient(1.04n~1.16 n, n is the layer number) of the first layer coiled hose. When the condition is stationary state, the pressure loss of other layer coiled hose can get get by multiplying the corresponding coefficient(1.07n~1.15n) of the first layer coiled hose.(6)When hard hose travelers are in different working conditions, the number of pressure loss of coiled hoses of hard hose traveler between dynamic and static state are nearly the same. The pressure loss of coiled hoses is finitely influence by the working state of hard hose travelers.(7)According to the test data of pressure losses of coiled hose in different working conditions, which verify calculation formula of the pressure loss of coiled hose in different flow patterns was proved. The results show that the theoretical value by caculation formula are in line with experimental value to pressure losses of coiled hose. So formulae can be used generic.(8)When hard hose travelers are working in field, hose’s pressure losses including pressure loss of straight hose along the route, pressure loss of coiled hose, and pressure loss of straight hose along the route which is caused by hoes bending because of the ground undulating.