多源激励下增压输送管路系统失稳机理与动力学特性研究

The spatial structure of pressurization feed pipeline system is complex and the constraint conditions are nonlinear. Under the service conditions, the system is affected by multi-source loads, including fluid internal pressure, cabin vibration, pressure oscillation of combustion chamber and so on. Due to the coupling effect of multi-source loads, the pipeline system is prone to large vibrations, which causes structural damages. Therefore, it is urgent to study the instability mechanism and complex dynamics of the pipeline system. This project aims at the research on dynamics modeling and analysis methods of pressurization feed pipeline system under multi-source excitation. The effects of geometric parameters and assembly methods of connection structures on the stiffness and damping of pipeline system will be explained. Fluid-solid coupling dynamics model of pipeline system under complex constraints will be established. The coupling mechanism of different excitation sources, such as fluid internal pressure, cabin vibration, pressure oscillation of combustion chamber, and so on, will be clarified. The nonlinear dynamic characteristics of piping systems under multi-source excitation will be revealed. This project can provide theoretical basis and technical support for dynamic design and vibration suppression of pressurization feed pipeline systems.

增压输送管路系统具有空间结构复杂、约束条件非线性等特点，在服役工况下会受到流体内压、舱体振动、燃烧室压力振荡等多源载荷的耦合作用，极易产生大幅振动从而引起结构损伤或破坏，迫切需要研究管路系统的失稳机理和复杂动力学问题。本项目拟开展多源激励下增压输送管路系统动力学建模与分析方法研究，阐明管路非线性连接结构几何参数、装配方式等因素对管路系统刚度和阻尼的影响规律，建立复杂约束条件下管路系统流固耦合动力学模型，厘清流体内压、舱体振动、燃烧室压力振荡等不同激励源的耦合作用机制，揭示多源激励下管路系统的失稳机理和非线性动力学特性。本项目可为增压输送管路系统动力学设计与分析及振动抑制提供理论依据和技术支撑。

通过项目负责人的认真组织，研究团队密切配合和合作，本项目基本完成了研究目标要求，在“微纳输流管道动力学特性分析”、“裂纹叶片转子动力学特性研究”、“含区间不确定参数的裂纹叶片动力学分析”三方面取得了重要研究成果。.针对微纳尺度粗糙微通道，发展了考虑表面粗糙度和速度滑移的输流管道流固耦合动力学建模方法，研究了表面粗糙度和稀薄效应作用下微纳尺度输流管道的不稳定性和动力学特性；针对旋转裂纹叶片的非线性振动问题，考虑裂纹对旋转叶片弯曲和拉伸位移的耦合影响，建立呼吸裂纹理论模型，提出预测裂纹叶片动力学响应的解析模型，并通过有限元方法对模型进行验证；结合裂纹叶片解析模型和基于Chebyshev包含函数的区间分析方法，发展针对裂纹叶片动力学特性的不确定性分析方法，揭示了裂纹位置、裂纹深度、气动载荷等不确定性因素对裂纹叶片动态响应的影响规律。.本项目在Microfluidic and Nanofluidics、Mechanical Systems and Signal Processing、Aerospace Science and Technology等期刊发表高水平SCI论文4篇，在投文章1篇，并申请国家发明专利5项，已授权3项，培养博士后1人。