Simulation Of Unsteady Flow In Fluid System And Precaution Of Water Hammer

A transient flow phenomenon will occur when a steady liquid flow met a certain incentive like water hammer. Once this phenomenon happens, the flow parameters, such as the flow pressure, will change not only with spatial position, but dramatically with time. For a long time, this phenomenon is responsible for huge economic loss and accident in industries like water utilities, petrochemical and nuclear power. Therefore, it is urgent that we need to find the regular pattern of water hammer and develop an effective system of water hammer precautionary measures for engineering practice.In this thesis, the main study subject is a crude pipeline connected a sealed underground caverns, while the research method has both the quickness of general formulas as well as the accuracy of AFT impulse software. First of all, the maximum water hammer pressure rise is calculated through the theoretical formula based on empirical data, after that we rapidly recognize and screen potential pipeline which may cause serious water hammer accident by engineering experience. Secondly, we use the software of water hammer to do water hammer simulation and calculation. By comparison, the estimated value is match to the value calculated by software basically.A synthesis methods of simulation and calculation of unsteady fluid simulation has been summarized and been applied in engineering project successfully. The valve designed by calculation can provide protection for piping systems without increase the pipeline design pressure, together with the SCADA system, they composed the most important precautionary measure regarding long-distance pipeline water hammer.