基于气蚀机理分析的航空柱塞泵叶轮增压系统匹配准则及设计方法研究

The life time of Chinese aviation piston pump is only 1/10 as much as the requirement of large aircraft, which restrict the development of Chinese large aircraft seriously. Cavitation, mainly caused by insufficient oil-absorption, is one of the factors which affect the life time of piston pump. In order to improve the oil-absorption capability, the centrifugal impeller booster is introduced in this project. However, it is difficult to search related foreign literatures, and the theory study of this field in domestic is almost still in blank. Firstly, a dynamic cavitation model is developed based on molecular diffusion theory and used to reveal the cavitation mechanism of the series system of centrifugal impellers and piston pump, and then find out the pressure and flow matching criterion of the series system; Wave propagation theory is introduced to reveal the coupled pressure fluctuation mechanism of booster and piston pump, and then present the method of minishing pressure fluctuation based on harmonic pressurization theory; Furthermore, the effect of impeller axial force on the life time of mainshaft bearing is studied, and then find out the method of balancing the axial force to enhance the durability of mainshaft bearing. At last, a series of tests will be carried out for verifying the models. This project produces a set of basic theory, simulation models, design approaches and test methods of piston pump with the centrifugal impeller booster. The benefits are not limited to greatly improve the life of piston pump(more than double), and also it can promote the development of self pressurization of volumetric pump. Therefore, this project is of great significance in theory and practical value in engineering.

我国航空柱塞泵工作寿命仅为民航飞机要求值的1/10，已成为制约大型飞机发展的关键零部件之一。柱塞泵因吸油不足产生气蚀和振动，是影响其寿命主要因素之一。项目通过集成增压叶轮实现大幅提高柱塞泵的吸油能力目的，国外无相关资料可供参考，国内理论研究基本处于空白。首先，基于分子扩散理论提出动态流体气蚀建模方法，揭示液力和液压串联增压系统的气蚀机理，提出叶轮增压系统的压力和流量匹配准则；其次，基于波传播理论揭示离心压力脉动和容积压力脉动的耦合机理，提出基于谐波增压理论的压力脉动抑制方法；接着，研究叶轮轴向力对主轴轴承寿命的影响规律，提出提高轴承寿命的叶轮轴向力平衡方法；最后进行对比实验验证。融合上述研究成果，形成一套柱塞泵叶轮增压系统的基础理论、仿真模型、设计方法和实验手段，不仅能够大幅提高柱塞泵的工作寿命(一倍以上)，而且能够推动液压泵自增压理论的形成和发展，具有重要理论意义和工程应用价值。

航空柱塞泵是机载液压系统的“心脏”，吸油不足是影响柱塞泵寿命和可靠性的主要因素之一，在柱塞泵进油口集成增压叶轮是解决吸油不足的有效方法，因此开展航空柱塞泵叶轮增压系统的匹配准则及设计方法研究，具有重要理论意义和工程应用价值。.项目通过集成增压离心叶轮以大幅提高柱塞泵的吸油能力，建立了柱塞泵叶轮增压系统耦合模型，揭示了柱塞泵叶轮增压系统气蚀机理和配油盘包角对吸排油性能的影响规律，得到了不同转速下柱塞泵入口临界压力，获得了叶轮形式（直叶片、弯曲叶片）和叶轮参数（出口宽度、进口直径、叶片包角、叶片数、时序位置）与柱塞泵匹配规律，设计了涡轮出口与柱塞泵进口需求P-Q曲线；从时域和频域角度揭示了不同转速、不同叶形及参数对叶轮出口压力脉动影响规律，揭示了叶轮出口流道形状、入口包角以及导叶等对叶轮增压系统的影响规律；建立了三维非定常对称湍流的叶轮轴向力计算模型，揭示了叶轮轴向力的变化规律，提出了柱塞泵增压叶轮的轴向力稳定方法；搭建了柱塞泵叶轮增压系统试验台，加工叶轮样件，编写了试验大纲，进行实验验证。.项目形成了一套柱塞泵叶轮增压系统的基础理论、仿真模型、设计方法以及实验手段，为我国高性能液压柱塞泵的研制提供技术支持。.本项目研究成果为：发表学术论文10篇，申请或授权发明专利11项，出版学术专著1部，参编航空标准1部，获中国航空学会科学技术一等奖1项。