考虑流固耦合效应,研究了含有非均匀轴向流简支管道的自由振动。采用Euler-Bernoulli梁模型和轴线不可伸长假定以及抛物线型的非均匀流速分布,借助开放系统的Hamiltion原理建立了含有非均匀轴向流管道流固耦合振动的控制方程。应用波动方法计算了一段简支管道在3种工况下的前5阶固有频率,并与文献中均匀轴向流的结果进行了对比,结果显示采用均匀轴向流假定时管道固有频率的计算结果比非均匀轴向流模型的结果偏高,其中对1阶固有频率计算的偏差最大。
Considering the fluid structure interaction(FSI) effect,the free vibration of pipe conveying non-uniform axial flow was studied based on Euler-Bernoulli beam theory and inextensible assumption.In terms of Hamilton′s principle for open system,the dynamic control equation of a simply supported pipe conveying fluid which velocity distribution of parabolic profile on the cross section was derived.In the numerical example,the wave propagation method was adopted to calculate the first five natural frequencies of the with simple supports at both ends in three different cases.Comparing the results with that of pipe conveying uniform axial flow,it is found that higher natural frequencies would be obtained when uniform flow assumption was adopted,especially for the first natural frequency.