流程泵径向叶轮内空化流动机理及动力学特性研究

The radial impeller of process pump is easy to cavitation for its low pressure at the suction of impeller, while the intensity of rotor-stator interaction (RSI) is obvious at the impeller outlet. As the close relationship between cavitation instabilities and intensity of RSI, cavitation instabilities of process pump are then become one of key problems for development and application. Although the pump with strong intensity of RSI is more prone to cavitation than the one with weak intensity of RSI, the inner flow pattern under cavitation condition for the pump and the correlation between cavitation instabilities and intensity of RSI are still not well revealed.. In this project, the generation and evaluation mechanism of the cavitating flow in the radial impeller is investigated based on the methods of theoretical analysis, numerical simulation and experimental methods. A new computational program with nonlinear RANS turbulence model considering the effects of rotation and curvature was developed, A hybrid RANS-LES method is then proposed to capture the structure of turbulent cavitating flows. The dynamics caused by cavitating flow in process pump will be studied to provide insight into the relation between cavitation development and flow dynamics of the pump. The relationship between cavitation instabilities and intensity of RSI will also be investigated, thus the cavitation instability mechanics in the radial impeller will be revealed. This will provide theoretical support to keep the process pump running safety under cavitation condition..

流程泵径向叶轮进口压力低，易出现空化；叶轮出口动静干涉明显，压力脉动较大。由于两者的相互作用强烈，造成不稳定空化问题是影响流程泵研制和应用的关键问题之一。虽然目前已知动静干涉强烈的泵内空化发生时的空化数远高于动静干涉弱的泵，但国内外还未能很好地揭示流程泵在空化状态下的汽液两相流动特性以及动静干涉现象与不稳定空化的关联机理。. 本项目拟通过理论分析、数值模拟和内外特性实验研究，深入研究流程泵径向叶轮内空化流动机理。建立适用于流程泵空化流动计算的计算策略，研究流程泵径向叶轮内空化流演变过程以及引起的流体动力特性，建立动静干涉与径向叶轮内空化流动不稳定之间的定量关系，为保证空化状态下流程泵安全平稳提供理论支撑。

流程泵径向叶轮进口压力低，易出现空化，引起的不稳定空化问题是影响流程泵研制和应用的关键问题之一。本项目从流程泵径向叶轮内空化流动机理和能量损失机理入手，通过理论分析、数值模拟和内外特性实验研究，分析了几何结构、动静干涉和流动参数变化对流程泵径向叶轮内空化流动结构的变化特征，建立适用于流程泵空化流动计算的数学模型和计算方法。开展了基于熵产理论的能量损失评估研究，并获得了空化条件下空化引起泵内能量变化和扬程下降的过程。开展了泵内压力脉动的实验测量和进口可视化流场测试，研究流程泵径向叶轮内空化流演变过程，分析了空化引起的泵压力波动和振动特性，提出了离心泵空化信号的时频域分析方法。为保证空化状态下流程泵安全平稳提供理论支撑。. 通过研究共发表论文8篇，其中SCI检索论文5篇，EI检索论文1篇，其他期刊论文1篇，会议论文1篇；专利9项，已授权发明专利4项；培养毕业硕士研究生2名，参加学术会议5次。