高转速下离心泵全流场非定常流动对转子动力特性的影响

Rotor system vibration is the key factor that affects the operation reliability of high speed centrifugal pump unit, and the unsteady flow in pump is closely related to vibration of rotor system. Based on the theoretical analysis, numerical simulation and physical experiment methods, systematic and in-depth study on dynamic characteristic characteristics of high speed centrifugal pump rotor system under unsteady flow condition will be carry out in this project. Firstly, the dynamic subgrid stress model for large eddy simulation based on the Reynolds stress constraints and Lagrange track average is to be constructed. Then, the accurate flow information is obtained under different mass flow rates and rotation speed conditions. Thirdly, the dynamic model and precise calculation method for rotor system is established under the action of the whole fluid exciting force. Finally, the impacts of pressure pulsation and fluid exciting force on fluid-induced vibration of pump rotor system is analyzed and the influence laws of unsteady flow on the fluid-induced vibration of pump rotor system are revealed. All the work will provide theoretical foundation and technological support for research method and industrial application of high performance high-power multistage process centrifugal pump.

转子系统振动是影响高速离心泵机组可靠运行的关键参数，泵内非定常流动与转子系统流体激振密切相关。本项目拟采用理论分析、数值模拟和实验的方法，通过转子系统动力特性模型构建和流体激励力对转子系统动力特性影响等关键科学问题对高转速工况下离心泵非定常流动作用下的转子系统动力特性开展研究。本项目首先采用修正的大涡模拟方法获得离心泵全流量、不同转速工况下高精度的流场信息，建立基于全流场流体激励力作用的转子系统动力特性模型及计算方法，分析泵内压力脉动和流体激励力对转子系统动力特性的影响，揭示泵内非定常流动特性对转子系统动力特性的影响规律，从而为低振动高性能高速离心泵的研发和应用提供支撑。

本项目针对航天液体火箭发动机和石油化工领域的高速离心泵及其系统的稳定性和可靠性问题，研究高转速下离心泵全流场非定常流动对转子系统动力特性的影响。主要研究内容及创新性成果如下：.通过构建修正的大涡模拟方法，计算并获得了全流量、高转速工况下离心泵内全流场高精度流场信息；分析了泵内受高转速、强剪切作用下的压力脉动时频域特征以及由此引起的主流场流体激励力对转子系统动力特性激励源的影响，研究了间隙流场流体激励力引起的等效刚度、阻尼和质量对转子系统支撑的影响，构建了基于全流场流体激励力作用下的转子系统振动特性计算方法；分析了非定常流体激励力作用下转子系统振动的时频域特征，揭示了泵内全流场非定常流动对转子系统动力特性的影响规律。