船舶复杂管路系统流固耦合响应计算方法研究

Piping systems are prevalent in marine device and petrochemical industry. Because of excitations arising both from inside and outside the pipe, the fluid-structure interaction (FSI) responses of pipe systems are induced. Sometimes these responses can be large enough to cause the conveying pipe and connected equipment to fail. Therefore, the research based on pipeline system primarily focused on vibration and noise generation mechanisms and propagation characteristics. And the main researches of this project are fluid and structural modeling and the improvement of transfer matrix algorithm, which involve: a shell-like beam model of FSI in multi-branched pipes of ships will be established, and the pipe wall radial force and displacement will be taken into account. Based on the shell-like beam model and the balance of displacement and force of branch point, the model for solving free and forced vibration response of branch pipeline will be deduced. And the damping springs along six freedoms and fluid impedance conditions will be introduced to simulate the complex boundary conditions. Here, the method of absorbing transfer matrix will be used and algorithms used for FSI response will be improved to avoid the distortion of higher frequencies. And the computational efficiency and accuracy will be improved greatly. Finally, a testing bed for measuring pipelines will be designed and built, and the verification tests will be carried out.

管路系统广泛应用于船舶动力、石油化工等领域中，这些管系在激励的作用下会产生流固耦合振动响应，严重时可能引发系统故障。因此对管路系统振动噪声产生机理、传播规律的研究一直受到国内外的重视。本项目即针对船舶管路系统流固耦合模型及计算方法开展研究。项目主要研究工作包括：引入管壁径向力和位移，探索建立管路流固耦合类壳的梁模型；将弹性阻尼结构和流体阻抗引入传递矩阵的模型中，建立管路中复杂的流体及结构边界条件；结合力和位移平衡条件，借鉴“吸收传递矩阵方法”的基本思想，推导、建立在任意支撑下的船舶管路分支部件传递矩阵程式化形式；探索混合模型结合部处的传递关系，并改进传统的管路流固耦合传递矩阵计算方法，消除其在长管道高频计算时的不稳定问题，从而在拓展其应用的频率范围的同时，保持较高的计算效率和计算精度；最后，搭建实验台架，通过实验验证所建立模型和计算方法的正确性。

针对船舶管路系统流固耦合模型及计算方法开展研究，主要研究工作包括：考虑管路壁面的径向应力、应变，流体压力、流速以及重力等因素的影响，改进完善了典型管路元件的流固耦合14方程数理模型并改进传统的管路流固耦合传递矩阵计算方法，消除其在长管道高频计算时的不稳定问题，从而在拓展其应用频率范围的同时，保持较高的计算效率和计算精度；将弹性阻尼结构和流体阻抗引入传递矩阵模型中，建立复杂的流体及管路边界条件；结合力和位移平衡条件，基于“吸收传递矩阵方法”，推导、建立在任意支撑下的船舶管路分支部件传递矩阵程式化形式；建立基于薄壳模型的直管路流固耦合方程并推导了其沿轴向和周向的传递矩阵；基于类梁壳模型和有限元传递矩阵法对薄壁直管和变径管的固有特性进行计算，探索梁壳混合模型结合部处的传递关系，并对其组合结构固有特性进行计算；通过 ANSYS 和 CFD 等商业软件和实验测量等多种手段，验证所建立模型和计算方法的正确性和适用性；最后利用所建立的模型和计算方法对管路流固耦合振动特性进行分析。