环瓣式浮环密封表面瑞利台阶型槽气体润滑动压特性

Gas Hydrodynamic Lubrication Performance of Split Floating Ring Seals with Rayleigh Step Grooves

关键词:  环瓣式浮环密封  气体润滑  瑞利台阶型槽  动压特性  型槽参数

Key words:  Split floating ring seal  Gas lubrication  Rayleigh step groove  Hydrodynamic effect  Groove parameters

摘要:

为提高密封气膜的开启能力以满足长寿命设计要求，基于气体润滑理论研究了环瓣式浮环密封表面瑞利台阶型槽的动压特性。采用有限差分方法，数值计算了密封气膜压力分布和动压效应，分析了操作参数和型槽几何参数对密封气膜压力和泄漏率的影响规律。结果表明，表面瑞利台阶型槽可以产生明显的气体润滑动压效应，可使得密封气膜平均压力和泄漏率分别增加38.6％和10.3％；型槽几何参数对动压效应影响明显，槽宽、槽数和槽深的增加均可使气膜平均压力增加；随着槽宽和槽数半径比的增加，无量纲平均压力先增加后减小。

Abstract:

In order to improve the opening capacity of seal gas film and meet the requirements of long life design of split floating ring seals， the hydrodynamic effect of Rayleigh step groove was studied based on gas lubrication theory. The pressure distribution and dynamic pressure effect of seal gas film were numerically calculated by finite difference method. Meanwhile， the effects of operation parameters and groove geometry parameters on film pressure and leakage rate were analyzed. The numerical results show that the surface Rayleigh step groove can produce obvious gas hydrodynamic effect， which can make the mean pressure and leakage rate increase by 38.6% and 10.3%， respectively. The groove geometric parameters present significant influence on the hydrodynamic effect， the mean gas film pressure increases with the increase of groove width， groove number and groove depth. Besides， with the increase of groove width and groove number radius ratio， the dimensionless mean pressure increases first and then decreases.