航空发动机气膜密封界面油液热驱浸润润滑机理与端面织构可控设计

Face contact wear is key factor that results in seal failure and restrict long-life design of gas seals. In the present project, surface texture is proposed to solve contact wear problem of gas seal faces by controling oil thermally-driven wetting so as to form oil lubrication, and study will be carried out on property of oil thermally-driven wetting lubrication at interfaces of aero-engine gas face seals and control with surface texture. The research will be conducted mainly in three aspects. Firstly, to develop gas-liquid double fluid thermohydrodynamic lubrication model based on gas thermohydrodynamic lubrication theory and oil thermally-driven wetting phenomenon, so as to analyze principle of temperature gradient of seal interfaces and mechanism of oil thermally-driven wetting. Secondly, to carry out design of surface texture and experiment of oil thermally-driven wetting, so as to investigate influence of surface texture on oil thermally-driven wetting in micro-clearance. Finally, to carry out seal test of oil thermally-driven wetting lubrication control with surface texture, in order to find out influence of oil thermally-driven wetting lubrication on anti-wear performance of seal faces and control method with surface texture. After comparison of theoretical and experimental results, to discuss the mechanism of oil thermally-driven wetting lubrication and to propose control method with surafce texture, so as to provide dependence for long-life design of aero-engine seal face. It will be helpful for the gas seal to solve contact wear problem in the cases of high amplitude and frequent start-stop, and to extend its application fields.

端面接触磨损是导致密封失效和制约气膜密封长寿命设计的关键因素。项目提出利用表面织构控制界面油液热驱浸润形成油膜润滑解决气膜密封接触磨损问题，拟开展航空发动机气膜密封界面油液热驱浸润润滑机理与端面织构可控设计研究，主要包括三个方面，其一是基于气体热动力润滑理论和界面油液热趋浸润现象，建立端面密封气液双流体热动力润滑模型，研究密封界面温度梯度变化规律和油液热趋浸润特性；其二是开展表面织构设计与油液热驱浸润实验，研究微米间隙中表面织构对油液热驱浸润特性的影响规律；其三是开展表面织构控制油液浸润润滑密封实验，研究表面织构对密封端面油液热驱浸润润滑特性的影响规律和控制方法。通过理论和实验结果的对比分析，探讨气膜密封界面油液热驱浸润润滑机理和表面织构控制方法，为航空发动机气膜密封的长寿命设计提供依据，对于解决气膜密封在反复启停、高振动工况下的接触磨损失效、拓展气膜密封应用领域具有非常重要的意义。

长寿命、高可靠密封技术是航空发动机工作效率提高、油耗降低，提高相关部件耐久性和工作寿命的关键因素。项目提出利用表面织构控制界面油液热驱浸润形成油膜润滑解决密封接触磨损问题以提高密封使用寿命，开展了航空发动机气膜密封界面油液热驱浸润润滑机理与端面织构可控设计研究，主要包括三个方面，其一是基于气体热动力润滑理论和界面油液热趋浸润现象，建立端面密封气液双流体热动力润滑模型，研究密封界面温度梯度变化规律和油液热趋浸润特性；其二是开展表面织构设计与油液热驱浸润实验，研究微米间隙中表面织构对油液热驱浸润特性的影响规律；其三是开展表面织构控制油液浸润润滑密封实验，研究表面织构对密封端面油液热驱浸润润滑特性的影响规律和控制方法。通过项目研究，建立了高温度梯度密封表面液体铺展的界面力学分析模型，揭示了高温度梯度密封表面液体铺展的驱动机制，并进一步研究获得了表面粗糙度、几何型槽边缘效应对液滴铺展的影响控制规律，有助于进一步认识和理解界面液体的运动行为和物理本质，研究结果具有重要的科学意义。同时，项目研究形成了端面密封气液双流体润滑技术，试验和实际应用表明该技术可以显著改善密封端面的润滑条件，降低密封磨损率，可显著提高现有航空发动机密封的使用寿命10倍以上，并可进一步推广至石油、石化等领域密封技术的提升，具有良好的工程应用和推广前景，具有重要的工程应用价值。