Research On Improvement Of Vibration Equation Of Axial Coupled Water Hammer

As for the fluid-filled pipe system, water hammer is an inevitable hydraulic transient phenomenon. Its huge pressure of water hammer which brings a very big hidden danger for pipe system, reseaching the dynamic characteristics of the water hammer has a special significance on actual fluid-filled pipe system. The reliability and validity of water hammer calculation is dependent on water hammer calculating theory, to refine and improve the basic equations for the calculation of coupled water hammer practical engineering that has important significance.Firstly, this paper has analysis of the problems wtih derivation of formula of the traditional water hammer and method of calculation detailed. We know, the continuity equation of traditional water hammer can be widely used for any non-constant flow or constant flow of hydraulic calculations, but in the event of a water hammer, and there is pressure wave velocity of fluid, stress wave velocity in the pipe, fluid velocity, and the traditional continuity equation did not reflect the situation in differential equations. In addition, the traditional theory of calculation of water hammer mainly focuses on the structural behavior of analysis, fluid of motion change due to the structure of motion-changed that has ignored, and it has a lot of simplification, that has led to an important part of system information is lost, the system can not better reflects the actual state of motion. This paper is based on the existing theory of water hammer and its coupled theory, for the calculated model of water hammer make further analysis and improvement, this paper puts forward the basic continuity equation which can be used to calculate the coupled water hammer.Then, the paper will correctes water hammer wave speed with coupled water hammer wave speed which consider coupled on the directions of vertical and horizontal, it has obtained a basic continuity equation that is used to calculate the coupled water hammer, and simplified the quations of fluid momentum and motion equationand of pipeline and physics equations to constitute improved axial4equation model.Comparison with analysis of the improved axial4-equation with the literature [21] of mathematical model, improved4-equation model could be used to calculate the coupled water hammer that is reliable and reasonable. Next, using the method of characteristics to handle with axial4-equation model, to get the ordinary differential equations, and it also derived by equation of characteristic of iterative format and boundary conditions in detail.