Water Hammer Perfect And Calculation Of The Equation

Water hammer is a sort of common pressure unsteady flow phenomenon. Firstly, this paper introduces the current elementary theory of water hammer calculation, including the mathematical model and the computational methods, then mainly points out that the continuity equation of current water hammer computation being used in the mathematical model can't satisfy condition of steady flow and existence of sin 6 is an unfairness question and so on. It shows that water hammer system equations in the current water hammer computation mathematical model exists certain disadvantages. The reasons which result in these questions are analyzed, it can be found that the influence of the slope of pipeline and the friction is not considered in the derivation of current water hammer pressure formula, but the effect of the slope pipeline is considered in the process of producing the water hammer calculative continuity equation. So it is inconsistent in the whole formula derivation. Moreover, during the process of producing equation, the concepts of the total derivative and the partial derivative are confused. These all are the basic reasons the continuity equation cannot satisfy the steady flow condition. Furthermore it does not match the momentum principle that the rule of change of water body between two fixed cross-sections in the pipeline is considered when water hammer motion equation is derived from momentum theorem.Against the unreasonable things in current water hammer equation, the new system of equations of water hammer calculation is obtained associating elasticity equation of conduit and elasticity equation of water by precise deduction using new idea in this paper. The new system of equations is as follows:The new system of water hammer equation ( I ) accords with steady flow...