内流流速时变输液直管动力特性的数值分析

根据Hamilton变分原理以及Euler-Bernoulli梁理论,推导出两端简支输液直管的自激振动微分方程,与传统的Housner方程相比,该方程增加了管内流体流速时变引起。的耦合力项,因而可用于分析内流流速时变情况下输液管线的动力特性。使用Hermite插值函数和Galerkin法对该微分方程进行离散,得到其有限元形式的表达式。运用该数学模型,通过数值算例,分析了内流流速时变输液直管的动力特性,得出了相应结论。

Numerical Analysis of Dynamic Characteristics of Straight Pipes with Time-varying Internal Flow Velocity

Based on Hamilton＇s principle and Euler-Bernoulli beam theory a self-excited vibration differential equation is derived for a straight pipe which are used for conveying fluid and simply supported at the both ends.In contrast to the traditional Housner＇s equation,a coupling-force term of internal flow velocity is added to the new equation to analyze the tube dynamic characteristics.The Hermite interpolation function and the Galerkin method are employed to discretize the differential equation to derive the finite element expression.By means of this mathematical model,the numerical calculation are conducted for certain cases to analyze the dynamical characteristics of the straight tubes of the time-varying internal flow velocity of conveying fluid and to draw the corresponding conclusions.