Numerical Analysis Pipeline Fluid - Solid Coupling Vibration Characteristics

Water hammer is a usual transient condition in the piping system, the vibrationof the piping system with consideration of fluid-structure interaction (FSI), whichcaused by the water hammer, should be studied from two aspects: the pulsing of fluxand pressure of the fluid, and the vibration characteristics of the piping structure. Thenumerical analysis method about the problems have critical guidance meaning for theoperation and design of the piping system, which has a broad background ofengineering applications and practical significance.The article, which based on the traditional water hammer method, pointed out thefeatures and shortcomings. According to the FSI four equations, provided the newmethod of charateristics (MOC) with FSI, which enhanced the analysis functions ofthe piping structure, can analysis the axial velocity and force of the structure besidethe pulsing of flux and pressure of the fluid. Meanwhile validated the reliability andaccuracy of the new method, by numerically analyzed a test mechanical piping systemin a reference.The actual piping system usually contain the components such as pump andvalve, so the numerical analysis of the boundary conditions about the components isan essential part of the numerical analysis for the vibration of piping system withconsideration FSI during water hammer condition. The research focused on thecommon components: the full characteristic curves of the pump, the hydrauliccharacteristics and operational principle of the valve, and built the correspondingmathematical models, achieved the establishment of the boundary models.Combined the new MOC and the boundary models of the pump and valve, thenew calculation program for water hammer was written. In the chapter of theapplication example, the typical piping system with pump and valve was chosen asthe analysis object, the pulsing of flux and pressure of the fluid, and the axialvibration characteristics of the piping structure during two schemes of valveshutdown--constant speed closing valve and two stages closing valve. Analyzed theinfluence of two different schemes of valve shutdown, and validated the reliability ofthe new numerical analysis method and calculation program through the analysis ofthe example.