离心泵进口流场畸变诱导低频频率特性的研究

Centrifugal pumps are widely used to almost all national economies such as energy, petrochemical industry, water transfer projects and agriculture irrigation projects. The control of low frequency characteristics of centrifugal pumps is very important for the safe operation of pumps and pump stations. Since the complexity of flow within centrifugal pumps, it is nearly blank for the researches on the low frequency characteristics induced by inlet flow distortion of centrifugal pumps. The mechanism and laws of the low frequency characteristics are going to be researched in this applied project. For a centrifugal pump with low specific speeds, their inlet flows will firstly be visualized by PIV and high speed camera under different flow rates. The law of inlet flow distortion will be found. The pressure pulsation, vibration and hrdrodynamical noise will be dynamically sampled at the same time. Their low frequencies will be picked up accurately. Secondly, under the flow rates with flow distortion, the unsteady flow within model pump will be simulated by LES. Based on the results of unsteady simulations, the structural responseof pump models will be simulated. The mechanism and laws of the low frequency characteristics induced by inlet flow distortion will be found. In the final, the control technologies of low frequency characteristics of centrifugal pumps will be obtained through the numerical optimization and experiments. After the project finished, the flow theories of centrifugal pumps will be further developed, and the control technologies of low frequency characteristics will be heightened. The project research is very meaningful for theory and valuable for engineering of centrifugal pumps.

离心泵广泛应用于能源、石化、调水工程及农业灌溉工程等国民经济各个领域，其低频特性控制对离心泵机组乃至泵站安全稳定运行至关重要。由于离心泵内部流动的复杂性，对进口流场畸变的机理及其诱导产生低频特性的机制认识尚属空白。本项目将对离心泵进口流场畸变与低频特性之间的关系及规律展开研究。针对低模型离心泵，在不同流量工况，采用PIV及高速摄像技术进行进口流场的流场显示，获得进口流场畸变规律；动态采集压力脉动、振动与水动力学噪声信号，准确提取其低频特性。在进口流场畸变流量工况下，进行全流道大涡模拟，进而进行模型泵水力激振响应仿真的模拟，获得进口流场畸变诱导产生低频特性的机制和规律。最后通过数值优选和试验验证，获得离心泵运行低频特性的振动控制技术。本项目的研究对丰富和发展离心泵内部流动理论，提高我国离心泵运行低频特性的主动控制水平，具有重要的理论与学术价值。

由于离心泵内部流动是复杂的三维非定常流动，许多流动现象的产生机理和流场结构仍不清楚，离心泵运行时低频特性研究的理论成果尚属空白，特别是由于进口流场畸变诱导产生的低频特性。通过本项目的研究，掌握了进口回流引起的流场畸变的机理和规律，以及其引起的低频汽蚀的规律，初步找到了进口回流引起的流场畸变与低频特性的有效控制技术。本项目的研究丰富了水力机械（泵）领域的内部流动理论，研究成果在工农业和国防上具有广阔的应用前景。.. 项目组发表论文23篇，其中被SCI收录或待收录12篇，被EI或待收录11篇，其中标注基金号的论文15篇；申请发明专利7项，获授权专利7项，其中发明专利3项。研究成果获国家科技进步二等奖1项。培养博士研究生3名，已毕业1名，培养硕士研究生6名，已毕业4名。