Analysis Of The Water Body's Vibration For Liquid-Filled Pipes And CAE Technology's Development And Application

The analysis of fluid-structure interaction of pipes has extensive engineering back-ground and important theoretical and research worthiness. In this paper, the vibration fre-quency of water body was researched based on solving the problem of abnormal vibration which appeared in the Three Gorges pipeline system in the case of small opening that may be caused by water body resonance. The advanced CAE simulation technology was used to simulate a series of fluid-filled tubes in order to find out various factors which may af-fect the water body vibration frequency. Some ways and conclusions received in this pa-per can be used as a reference for the pipeline design.The contents and results of this study are mainly as follows:1. Secondary developments of MSC simulation softwares. Functions such as parametric modeling, user interacting with data and menu designing are achieved by fully use of the PCL language. Modeling requests which are difficult for the manual operation are realized and the modeling speed is enhanced through these functions; The Time-depen- dent boundary conditons are added for MSC.Dytran through user defin-ing subroutines which are compiled with the Fortran language.2. Liquid-filled elbow pipe's coupling equations derivation. Based on the ring coordinate, the Walker and Phillips's 6-equations model is extended from the continuity equations, differential control equations of liquid and differential motions equations of thin shell to a new model that can be applied to the elbow pipe. It's proved theoretically that the water body's inherent frequency increases along with the pipeline bending increasing.3. CAE research for liquid-structure interaction vibration. Numerical simulations are made for models with different restrictive conditions, exits of different opening and bendings to identify their impact on the water body's inherent frequency. After com-putation, we find out that under the same other conditions, the stronger Poisson cou-pling is, the smaller water body's frequency is.