离心泵进口畸变流诱导噪声作用机理研究

The control of the flow-induced noise in centrifugal pumps is very important for both environmental protection and military operation. Due to the complexity flow characteristic within centrifugal pumps, it is nearly blank for the researchers on the noise generation mechanism caused by inlet distortion of a centrifugal pump. This project will focus on the relationship between the flow-induced noise and distortion flow originated from import instability flow, backflow from the impeller and leading edge cavitation. Firstly, for a centrifugal pump model, the flow distortion characteristic at inlet field will be visualized by the high-speed photography techniques combined with numerical simulation under different flow rates and different types of import flow; Secondly, a new method based on the two-port transmission model for quantifying the source of flow dynamic noise in centrifugal pumps will be developed to solve the disturbance from the pipe. Combined with dynamic signal collection such as pressure pulsation and radiated noise, acoustic analysis in the frequency domain will be processed for this inlet distortion flow field characteristics; Thirdly, a full flow field pump model will be built to calculate the internal flow field and process acoustic simulation of centrifugal pumps taking vibro-acoustic interaction effect into account; Finally, the noise generation mechanism caused by the inlet distortion of centrifugal pumps will be revealed based on the numerical and experimental results. The project will provide a theoretical basis to enrich the internal flow theory and develop a low-noise design method of centrifugal pumps.

控制离心泵运行时产生的噪声对环境保护和解决船舰等隐秘性问题至关重要。由于离心泵内部不稳定流动的复杂性，国内外还未能很好地揭示其进口畸变流引起的流场特性及其诱导噪声的作用机理。本项目将针对离心泵进口不稳定来流、回流和叶片前缘空化等引起的畸变流场特性与流致噪声之间的关系进行深入研究。首先基于某离心泵模型，结合高速摄影和流场数值模拟进行进口流场的流态显示，获得不同入流条件和不同流量下进口流场畸变的规律；其次发展四端网络声学模型以解决管道系统和离心泵流动噪声源之间的耦合问题，并结合流场压力脉动和辐射噪声信号的动态采集定量解析模型泵进口流场畸变时的声学特性；然后建立模型泵全流道流场求解策略，开发考虑泵体声振耦合作用后的离心泵流致噪声仿真程序；最后通过分析数值计算和实验结果，揭示离心泵进口畸变流诱导噪声的作用机理，为丰富和发展离心泵内部流动理论、提高我国离心泵低噪声设计水平提供理论基础。

随着泵向高速化、大功率方向发展，其噪声问题日趋严重，已成为环保问题重要的控制对象。由于离心泵内部不稳定流动的复杂性，国内外还未能很好地揭示其进口畸变流引起的流场特性及其诱导噪声的作用机理。本项目采用理论分析、实验研究和和数值模拟相结合的手段对回流、空化、不均匀来流等进口畸变现象进行了研究。发展了无源四端网络声学模型，解决了管道系统和离心泵流动噪声源之间的耦合问题，实验研究了不同运行工况下离心泵的流动噪声和流动诱导结构辐射噪声相关规律；对非均匀进流情况下泵性能损失机理和流场畸变特性及其诱导振动噪声机理进行了初步分析；建立了一种流-固-声多物理场一体求解的流动诱导噪声数值模拟方法，考虑了求解离心泵流致噪声时泵体的声振耦合作用；以叶频噪声声压级、扬程、效率和轴功率这四个指标作为判断标准，首次采用权矩阵方法借助数值模拟技术对离心泵叶轮进行多目标优化设计，得到一组水力模型优化方案；揭示了多级离心泵内部流动与诱导的结构辐射噪声间的关系，并通过优化叶轮/导叶匹配进行了多级泵低噪声设计。. 项目组出版著作2部，发表论文22篇，其中被SCI收录10篇，被EI收录7篇，获授权国家发明专利6项。研究成果获教育部科技进步二等奖1项、山东省科技进步二等奖1项、机械工业联合会三等奖1项。培养博士研究生3名，硕士研究生4名。本项目的研究丰富了水力机械（泵）领域的内部流动理论，具有重要的理论意义。项目研究成果正在对噪声性能要求较高的汽车电子水泵和空调系用管道泵产品研发上进行应用，在工农业和国防领域具有广阔的应用前景。