指尖密封泄漏和渐进磨损机理研究

The complex working states of the aero-engine has prominent influence on the performance of the finger seal that locates in the aero-engine. But so far, the dynamic performance analysis of the finger seal under the complex working states has not been investigated yet. Based on this, the theoretical analysis, numerical simulation and experimental research are integrated, and the five parts researches are carried out in this project. First, the effect of fluid, which is located in the gap between two adjacent finger sticks, on the finger stick deformation is researched. Second, the model of finger seal dynamic performance analysis is established under considering high temperature creep effect, and then the deterioration law of carbon-carbon (C/C) composite finger seal performance is obtained in the service period by the model. Third, the dynamic performance analysis model of finger seal considering progressive wear is presented to predict the life time of finger seal. Fourth, the fluid-solid coupling numerical model of C/C composite finger seal is established by the equivalent dynamic model based on distributed masses, and the leakage time-varying feature is revealed. Fifth, the equivalent dynamic model of C/C composite finger seal under complex working states is presented, and the effect of complex working states on the dynamic performance of the C/C composite finger seal is studied. The research is conducive to promote dynamic analysis technology of finger seal to engineering application, and also improve the theoretical research system and methodology of finger seal. Therefore that has higher academic significance and engineering application value.

航空发动机复杂的工作环境会对所处其中的指尖密封性能产生较大影响。但迄今为止，国内外鲜有研究工作涉及这一问题。基于此，本项目以理论分析、数值模拟和试验研究相结合的方式，重点开展五个方面的研究：1) 以相邻指尖梁和梁缝隙间流体为对象，研究梁缝隙间流体压力对指尖梁变形的影响规律；2) 构建考虑高温蠕变效应的C/C复合材料指尖密封动态性能分析模型，获得服役期内指尖密封性能劣化的规律；3) 提出考虑渐进磨损的指尖密封动态性能分析模型，以预估指尖密封的使用寿命；4) 建立基于等效动力学模型的C/C复合材料指尖密封流-固耦合数值分析模型，揭示指尖密封泄漏率的时变特征；5) 构建复合工作状态下的指尖密封等效动力学模型，探究复合工作状态对指尖密封动态性能的影响规律。本项目研究不仅有助于指尖密封动态分析技术在其工程分析设计中的实用化，也在一定程度上对指尖密封动力学研究理论体系和方法有所完善，有较高的学术意义。

本项目以突破考虑渐进磨损效应的指尖密封流-固耦合性能分析方法关键技术为研究目标，研究渐进磨损效应对指尖密封泄漏间隙和接触压力的影响，建立指尖密封泄漏性能劣化规律模型；构建复合工作状态下的指尖密封等效动力学模型，探究复合工作状态对指尖密封动态性能的影响规律；研究指尖密封泄漏间隙内流体压力与指尖密封接触压力间的关联关系，解决时变效应的指尖密封性能分析难题，该方法为其他类型动密封性能分析与寿命评估提供技术支持，完成了课题的全部研究目标。