Study On Water Hammer Calculation Method And Program Design Of Liquid Pipeline

Water hammer phenomenon has been a case of the unsafe operation of the pipeline, which can not be avoided due to some objective factors, for the design and production operations in the pipeline where water hammer easily affected need to consider this factor. Currently, calculation of pressure for water hammer is usually use foreign pipeline simulation software, the main function of these software is used to simulate the normal operation of the pipeline, but these pipeline simulation software are unavailable non-normal operation, such as water hammer which usually with great fluctuation of water pressure and change fast. So a precise calculation of water hammer tool is in high value when you need to consider these factors.Through preliminary research to understand the main method of calculation and to know their strengths and weaknesses, then select the method of characteristics and explicit difference method for comparison, and the introduction of adaptive mesh, to further improve the accuracy.For liquid pipe model study, we selected two water hammer models stop pumping and throttle down as calculation model to study. Using Matlab tools to verify the method of characteristics and explicit difference method, comparison the results of the of the two calculation methods, and finally we selected the explicit difference method for calculating water hammer calculation program. Meanwhile, we choose density as a variable, so the number of such variables reached to3. The purpose is that a great influence on the density of water hammer wave speed and density of the fluid in the tube is not uniform and change.Using visual studio C#programming tools to complete the water hammer simulation program.The paper analysis of two specific cases of water hammer simulatio. Through simulating pipeline and control valves sudden power failure occurs in the closure of water hammer in pump unit, the results are as follows:(1) In the case of pump unit outages, water hammer pressure rises quickly in a short time, then change more gentle in the next time, due to the pressure of site after pumping station is higher than the pressure of site before the station, so that the pumping station drying conditions occur. Finally, when the getting in pressure is higher than the outgoing pressure, the tube fluid flow through the pumping station;(2) In the case of failure to control valve-off, the water pressure in water hammer wave hit return to the valve, the pressure of end of valve reach to peak, after then the water hammer pressure gradually decreases, and the velocity of wave has slowed down. Under different time of valve-off, we can the longer the length of the valve-off the smaller of the maximum water hammer pressure and the later it occur.Through the study of water hammer calculation, we get a more accurate calculation of water hammer, and further improve the calculation accuracy by using of the adaptive mesh grid. Preparation of water hammer simulation program, which has capabilities of some water hammer modeling, can analysis certain problems of water hammer with practicality.