Experimental Research On Pumping Water By Long Distance Siphon

Usually, water delivery discharge of siphon piping is calculated by the formula (?).But in the hydraulic model test about long distance siphon piping engineering of Xinjiang, the measured discharge of the pipe is very different from the design one which is calculated by the formula. Based on this test results, in this paper, the water discharge's calculation method of siphon pipe has been discussed through model tests at the laboratory. The results indicate that siphon pipe discharge is influenced not only by the usual factors such as the form of pipe arrangement, caliber,pipe line, pipe roughness and water level, but also by the setting height of siphon. Some conclusions can be drawn by model tests:(1) In order to content with similar demand of vaporization, the siphon piping's setting height in the model can't be designed only by gravity similitude principe.(2) Under conditions of same water level, the water delivery discharge gradually decreases along with the increment of setting height, the discharge calculate formulation attached with setting height of long siphon piping is derived.(3) Observed flow vaporization of vacuum delivery pipe in differenct working conditions, ,while pipe cross-section velocity is bigger than air bubble's competent velocity, siphon pipe can work well, otherwise, water interception will happen.(4) The air exhaust pattern and air relief installation's location for long-distance siphon pipe have been studied by the model tests.