螺旋槽端面微间隙高速气流润滑密封特性

考虑入口气流压力损失和出口阻塞效应,建立了微间隙端面高速气体润滑密封分析数学模型,对螺旋槽端面微间隙高速气流润滑密封特性进行研究.重点分析了不同密封间隙、密封压力和转速等工况条件下,入口压力损失和出口阻塞效应对开启力、泄漏率及气膜刚度等密封特性参数的影响规律.结果表明:高速气体阻塞效应使出口压力高于环境压力,压力损失使入口气膜压力下降,导致泄漏率和气膜刚度明显下降,并使开启力增加.随着密封压力和密封间隙的增加,阻塞效应增强,导致泄漏率和气膜刚度显著降低.密封压力10 MPa时,泄漏率降低可达20%,气膜刚度的下降可达30%以上.

Properties of High Speed Airflow Lubrication in Micro- Clearance of Spiral-Groove Face Seals

The properties of high speed airflow lubrication in micro-clearance of spiral-groove face seals were studied with consideration of entrance pressure loss and choked flow effect. The seal parameters such as opening force, leakage and gas film stiffness were numerically calculated and discussed under different conditions of clearance, seal pressure and rotational speed. The results show that the choked flow effect made the exit pressure higher than the ambient pressure, while the entrance pressure loss led to inlet pressure drop. These resulted in significant decrease of the leakage rate and the gas film stiffness, but increase of the opening force. The choked flow effect increased with increasing seal pressure and seal clearance, which led to obvious decrease of the leakage rate and the gas film stiffness. When the seal pressure reached up to 10MPa, the leakage rate decreased 20%, meanwhile the gas film stiffness decreased more than 30%.