面向复杂管路网络流固耦合的阻抗分析方法研究

The theory for fluid-structure interaction (FSI) of complex pipelines with various supports, excitations and multi-branch configurations is still insufficient, which limits the capability of designing and verification of practical piping systems. . A novel methodology of FSI based on the impedance theory is proposed in this project, focusing on the dynamic analysis and prediction of piping systems with complex supports and multi-source excitations. The project will study the dynamics of complex supports and constrains precisely, and construct their impedance models for the solution of the whole FSI system. The proposed FSI impedance method developed from the conventional impedance theory is capable of describing the interactive dynamic behaviour of fluid and solid, to solve problems of the multi-source vibration coupling and of the complex configuration calculation. A set of methods for FSI prediction and frequency-domain analysis will be obtained, which would be validated by the experimental work. . The research is essential for the filed of pipe vibration and FSI theory, as well as the design and reliability of complex liquid-pipe systems.

目前，对于具有复杂支撑、多源激励和多分支构型的复杂管路系统的流固耦合振动，相关理论较为缺乏，制约了对实际管路系统的设计和试验能力。. 本课题提出面向复杂管路网络的流固耦合的阻抗分析方法，实现对系统的动力学分析与行为预测。课题在研究管道复杂支撑约束的动力学特性基础上，建立其阻抗模型，从而实现对含支撑的管路的流固耦合分析。在传统阻抗理论基础上拓展、提出了新的阻抗方法，能够描述流体与固体的耦合动力学行为，解决多源激励问题和多分支构型计算问题。课题拟建立一套有效的管路流固耦合振动预测和频域分析方法，并通过相应的实验研究验证理论的有效性。. 本研究对于管路振动、流固耦合理论具有重要的学术价值，对于以飞机液压管路为代表的复杂管网设计、提高系统可靠性具有重要应用意义。

以飞机液压管路系统为代表的的复杂管路系统，具有空间构型复杂、支撑条件复杂、多源激励输入的特点与挑战，目前已有的理论不能很好地解决这些问题。本项目以频域建模求解方法为目标，得到复杂管路的频域特性响应。研究首先建立管夹等复杂支撑约束的阻抗模型，并将其与管路流固耦合模型进行融合，实现对含支撑的管路流固耦合的计算。在分支节点模型的基础上，给出了其含支撑的阻抗表达形式。因此可以将多源振动输入点视为一个具有复杂约束的分支点模型，进行建模与求解。通过实验与仿真对比验证，证明了结构振动输入下的管路流固耦合方法的有效性，同时也验证了多源激励模型、支撑阻抗模型的有效性。本研究的学术性在于完整给出了复杂支撑、复杂边界管路的建模仿真方法，对于提高复杂管路的设计能力、预测管路振动水平、故障仿真与排除具有实际的应用价值。