水锤冲击时管路系统流固耦合响应的特征线分析方法研究

本文以Wiggert 和Hatfield[3]的特征线分析方法为基础,研究管路在水锤冲击下考虑泊松耦合时流体和结构的瞬态响应.推导了分别对应于管中流体压缩波和管壁中纵波的特征关系式和相容方程,并联合采用空间插值和显式时间插值进行数值求解.针对经典的水锤压力冲击的算例,将边界和初始条件离散化,编制了MATLAB程序进行计算,获得管道中流体压力和流速及轴向应力和振动速度的时程曲线,计算结果与理论分析相当吻合.根据计算结果,提出了对于实际管路设计和水锤防护有益的结论.鉴于特征线法本身的优势,有望在管路系统抗冲击设计分析和防护研究中得到进一步的应用.

Application of MOC to calculation of fluid-structural coupling response of piping system under impact of waterhammer

Based on Wiggert and Hatfield's MOC(method of characteristic), the transient response of fluid and structure of piping system under impact of waterhammer is investigated,taking account into the effect of Poisson coupling.The characteristic relations and compatible equations corresponding to compressive waves in fluid and longitudinal waves in the wall of pipe are derived simultaneously,the numerical solution is carried out by using spatial interpolation in combination with explicit temporal interpolation.As an example of calculation, the classic waterhammer problem of pressure jump from the upstream into pipe is solved by applying the initial and boundary condition and calculating in MATLAB code,the time histories of pressure and particle velocity in fluid as well as axial stress and velocity in pipe wall are obtained.The computational results are fairly consistent with those of theoretical analysis.Through the obtained results, suggestions about practical pipe design and protection from waterhammer are proposed. Due to the inherent merits of MOC,it is hoped that further application of MOC should been put into the anti-shock design and analysis of piping system.