端面石墨密封因其具有良好的耐磨特性和耐高温性能，常用于航空发动机滑油系统中高温、高速工况下传动系统润滑油的密封。本文以某航空发动机用接触式端面石墨密封为研究对象，首先建立了基于平均雷诺方程、未考虑磨损的流固热耦合混合润滑模型，针对减少泄漏量提出了密封优化设计方案;从密封寿命预测需求出发，提出了考虑均匀磨损与多场耦合混合润滑模型耦合的密封性能分析模型，为密封寿命预测提供了基础。通过自主研制的端面密封台架实验对上述模型及密封优化结果进行了初步验证。主要内容包括:发展了一种基于 MATLAB与COMSOL平台工具的接触式端面密封流固热耦合模型。通过求解平均雷诺方程，并与 COMSOL 的热力变形计算结果进行耦合，对给定结构端面石墨密封性能进行了分析和计算。研究结果表明，该结构端面石墨密封在航空发动机工况下，初始密封间隙呈发散，温升较高，泄漏量为 3.48mL/h。基于本文提出的流固热耦合模型，讨论了压差、转速对密封性能的影响，进而揭示出该密封的作用机理。结果表明，与密封压力比较，转速对密封性能影响更加显著;以减小泄漏量为目标，提出改变端面形状和改变静环结构两种优化方案。结果表明，两种方案均可以实现密封间隙由初始发散变为收敛，有效减小泄漏量，其中改变静环结构的作用效果更明显，且更具有工艺可行性。根据端面石墨密封磨损失效为主要形式的寿命预测需求，建立了以 Archard 粘着磨损模型为基础的端面密封稳定工作状态均匀磨损模型。以两种静环结构优化方案为例，运用均匀磨损模型进行了密封性能分析；分别以密封端面初始磨合阶 段与稳定工作阶段为对象，提出了简单的密封寿命预测模型。结果表明，本文提出的泄漏量减小最大的密封结构，其磨损会增大导致寿命减少。因此，接触式密封的优化是一个平衡寿命与泄漏量的过程。独立设计，安装，调试了全尺寸端面密封高速实验台。进行了初始方案与部分改进方案的密封性能对比实验，提出了端面密封泄漏量，端面温度，端面磨损测量方案，并进行了重复实验。将实验结果与均匀磨损模型进行对比，结果表明， 实验结果比较稳定、是可重复与可信的，且基本验证了均匀磨损模型对密封端面变形、温升等的预测；针对泄漏量的预测分析模型还存在不足，需进一步完善。

Graphite mechanical seal is often used in the high-temperature and high-speed driving system of the aero-engine lubricating oil system because of its good wear-resistant and high-temperature resistance. In this paper, the contact mechanical seal for aero-engine is taken as the research object. Firstly, a fluid solid heat coupling lubrication model based on the average Reynolds equation and without considering the wear is established, and a sealing optimization design scheme is proposed to reduce the leakage. From the perspective of sealing life prediction, a sealing performance analysis model considering the uniform wear and multi field coupling lubrication model film thickness is proposed. It provides the basis for seal life prediction. Through the self-developed end mechanical seal bench test, the above model and seal optimization results are preliminarily verified. The main contents include:A fluid solid thermal coupling model of contact mechanical seal based on MATLAB and COMSOL is developed. By solving the average Reynolds equation and coupling with the thermal deformation calculation results of COMSOL, the performance of a given structure mechanical seal is analyzed and calculated. The results show that under the condition of aero-engine, the initial seal clearance of the structure is divergent, the temperature rise is high, and the leakage is 3.48ml/h.Based on the fluid solid thermal coupling model proposed in this paper, the influence of pressure difference and rotating speed on the sealing performance is discussed, and the mechanism of the sealing is revealed. The results show that, compared with the sealing pressure, the rotating speed has a more significant impact on the sealing performance; in order to reduce the leakage, two optimization schemes are proposed: changing the end face shape and changing the static ring structure. The results show that both schemes can realize the change of seal clearance from initial divergence to convergence and effectively reduce the leakage. The effect of changing the static ring structure is more obvious and more feasible.According to the demand of life prediction under the main form of wear failure of mechanical seal, a uniform wear model based on the Archard adhesive wear model is established. Taking two optimization schemes of static ring shape as an example, the seal performance is analyzed by using the uniform wear model, and a simple seal life prediction model is proposed based on the initial running in stage and the stable working stage of the seal face. The results show that the sealing structure with the largest leakage reduction proposed in this paper will increase wear and lead to a decrease in service life. Therefore, the optimization of contact seal is a process of balancing life and leakage.Independent design, installation and commissioning of the full-scale mechanical seal high-speed experimental platform. Compared the initial scheme with some improved schemes, the leakage, temperature and wear measurement scheme of the end mechanical seal were proposed, and repeated experiments were carried out. Comparing the experimental results with the uniform wear model, the results show that the experimental results are relatively stable, repeatable and credible, and basically verify the prediction of the uniform wear model on the seal face deformation, temperature rise, etc.; the prediction analysis model for the leakage amount is still insufficient, which needs to be further improved.