关键词: 流固耦合 , 特征线法 , 气液两相流 , 含气率 , 压力波速

Abstract: Based on the four － equation model describing the fluid structure interaction （FSI） in axial vibration for liquid －
filled piping system ， the effects of Poisson ，friction and junction coupling on the axial response of the piping system were
studied ．The method of characteristics （MOC） was described in detail and the transient response of the reservoir － pipe － valve
system to instantly valve closure was numerically simulated ．The numerical analyses show that the FSI can not be ignored ．The
Friction coupling is less important while the junction and Poisson coupling are more important ．The common calculation models
of pressure wave speed were reviewed ，the optimization calculation model was recommended and the effects of void fraction on
the speed were analyzed ，aiming at providing a theoretical guide for further study of the FSI analysis of gas － liquid two － phase
flow pipes

Key words: Fluid structure interaction , Method of characteristics , Gas － liquid two － phase flow , Void fraction , Pressure wave velocity