湍流激励下结构振动特性的半解析半数值算法研究

Semi-analytical and semi-numerical method for calculating the vibration characteristics of structure excited by turbulent boundary layer

提出了一种基于随机激励理论计算结构在湍流激励下振动特性的半解析半数值算法。对经典的corcos模型给出的湍流脉动压力功率谱密度表达式进行离散得到湍流脉动压力功率谱密度矩阵作为输入,采用有限元边界元数值算法计算出考虑流固耦合作用时结构的频响函数矩阵,进而结合随机理论计算出结构在湍流激励下速度响应的功率谱密度矩阵,同已有文献中解析法计算结果吻合较好,证明了计算方法的正确性。之后,将本文计算方法应用到湍流激励下单层圆柱壳振动特性的计算研究。结果表明:半解析半数值方法将经典的corcos模型和有限元边界元数值算法相结合,能够很好解决一些外形规则内部结构复杂的工程问题,具有较强的工程应用价值。

A semi-analytical and semi-numerical method for calculating the vibration characteristic of structure excited by turbulent boundary layer based on random excitation theory is presented.The power spectra density expression of the excitation caused by turbulent boundary layer given by Corcos is dispersed into matrix form as input.Combined with the frequency response function matrix considering fluid-structure interaction calculated by FEM/BEM methods,the power spectral density of the structure velocity is calculated.The numeric method result is quite identical with the analytical method mentioned in references,proving the numeric one to be correct.Thus,this method is used to calculate the vibro-acoustic characteristic of single cylindrical shells excited by turbulent boundary layer.The result shows that this semi-analytical and semi-numerical method is quite suitable for solving practical engineer projects the structure of which has a simple and regular outer shape but has quite complicated inner structures such as machinery,pipe system and so on.