离心泵空化非定常动力特性与空蚀机理研究

The stability and reliability of operating centrifugal pumps are often threatened by cavitation phenomenon, the fluid dynamics caused by the inception, development and collapse of the cavities are the main reasons to induce erosion, vibration and acoustic of centrifugal pumps, which is always one of the critical issues to be solved in pump industry. In this project, the transient dynamics caused by cavitating flow and cavitation erosion mechanism in centrifugal pumps will be lucubrated via experiment test, numerical calculation and theoretical analysis. This work will provide a theoretical foundation to improve the reliability and efficiency of centrifugal pumps..In order to investigate and control cavitation and erosion phenomenon in centrifugal pumps, an experimental system and data processing technology for measurements will be developed, and the database of cavitation and erosion will be established. The relation among the evolution process of the cavities, energy characteristics of centrifugal pumps, fluctuating pressure on blade, vibration and acoustic will be studied, the transient dynamics and mechanism caused by cavitating flow in centrifugal pumps will be revealed. The turbulence and cavitation model for the unsteady cavitating flow computations in centrifugal pumps will be studied, and the models will focus on the influence of rotation effect and large curvature structure characteristics on cavitating flow. In order to reveal the cavitation mechanism in centrifugal pumps, the transient characteristics and propagation law of impact pressure caused by collapse of the cavities will be studied, and the prediction method of cavitation erosion will be proposed.

空化空蚀严重影响离心泵运行的稳定性和可靠性，空泡的初生、发展和溃灭诱导的非定常流体力是引起离心泵空蚀、振动和噪声的关键因素，是泵领域丞待解决的关键科学问题之一。本项目拟通过实验测量、数值计算和理论分析相结合的方法，深入研究离心泵空化非定常动力特性和空蚀机理。为离心泵的设计和高效可靠运行提供理论基础。.针对离心泵内部的空化空蚀问题，发展系统的离心泵空化空蚀实验测量及其数据分析处理技术，建立离心泵空化空蚀特性实验数据库；研究空化初生、发展和溃灭与离心泵能量特性、叶片表面脉动压力、振动和噪声的内在关系，揭示离心泵内部非定常空化动力特性及其机理；考虑离心泵旋转效应和大曲率结构特征对空化流动的影响，发展适用于离心泵内部非定常空化流动的计算模型；研究离心泵空化溃灭引起的冲击压强瞬变特性和传播规律及其与蚀坑大小和分布的相互作用机制，深入揭示离心泵内部空蚀机理，并建立空蚀预测方法。

空化空蚀是制约离心泵向大型化、高速化和高性能方向发展的重要因素，是亟需解决的关键科学问题之一。本项目针对离心泵空化非定常动力特性和空蚀机理进行深入研究，建立了离心泵空化动力特性实验测量平台，实现了离心泵瞬态空化形态观测、脉动压力、空化诱导振动、噪声的测量和分析，发展了系统的离心泵空化空蚀实验测量及其数据分析处理技术，对不同流量下离心泵空化前后不同信号的变化进行分析，建立了离心泵空化信号特性分析及阈值确定方法；试验研究了不同表面涂层材料的抗空蚀性能，获得了涂层厚度对离心泵性能、内部流动、叶轮轴向力和径向力等特性的影响规律，为空蚀防护技术提供了基础；掌握了离心泵空化初生、发展和溃灭过程与泵能量特性、脉动压力、振动和噪声等动力特性的内在关系，揭示了离心泵内部非定常空化动力特性及其机理，建立了离心泵空化状态识别方法，开发了空化状态识别系统；以FBM模型和DCM模型的修正思想为基础，发展了一种适用与离心泵内部非定常空化流动的PANS模型，提高了离心泵空化流动的预测精度，阐明了离心泵的空化性能、内部空泡形态的发展变化、瞬态速度流场的分布以及扬程和压力的非定常特性。设计并搭建了用于获取蚀坑图像的光路系统，开发了获取蚀坑数量及分布的图像处理程序，建立了空蚀预测方法。. 项目研究具有较高的科学意义和学术价值，应用前景广阔。研究成果进一步揭示了离心泵空化流动特性及空蚀机理，丰富了空化空蚀理论，为离心泵设计和高效可靠运行提供了理论基础。. 本项目出版专著1部，发表论文18 篇，其中SCI 检索12 篇、EI 检索4篇；授权发明专利6件，登记软件著作权3件；获教育部科技进步二等奖1项，机械工业联合会科技进步三等奖1项；培养硕士研究生5名、博士研究生1名。.