上游泵送机械密封液膜刚度的计算与分析

基于N-S方程和连续性方程,并用PH线性化及迭代法,对于上游泵送机械密封两端面间液膜流场的广义雷诺方程进行求解,并利用Maple程序计算在不同转速、压力、螺旋角、槽数、槽深下的液膜刚度。结果表明:随着螺旋角、槽数、槽深(几何参数)的变化,等温不可压缩流体条件下的液膜刚度随之发生变化,并且呈现非线性关系;随着介质压力、转速(工况条件)的增加,液膜刚度也随之增加,且呈线性关系。

Calculation and Analysis of Upstream Pumping Mechanical Seal Liquid Film Stiffness

The key technology of mechanical seal is stability and the liquid film stiffness is one of main pa-rameters which will affect the seal stability.Based on the N-S equation and continuity equation and applied the PH linearization and iteration method to solve the equation of generalized Reynolds equation of liquid film flow field between two ends of upstream pumping mechanical seal,obtain the analytical formula of liq-uid film thrust and then obtain the approximately analytic formula of liquid film stiffness.Apply the Maple program to calculate the liquid film stiffness of different rotating speed,pressure,helical angle,groove number and groove depth so that to analyze the liquid film characteristic of this upstream pumping me-chanical seal structure.The calculation results show that along with the changes of helical angle,groove number and groove depth (geometrical parameter),the liquid film in the condition of isothermal incom-pressible fluid changes accordingly and presents the non-linear relationship;along with the increase of me-dium pressure and rotating speed (working condition),the stiffness of liquid film increases accordingly and presents the linear relationship.According to abovementioned results,the seal structure with appropriate parameters such as groove quantity and helical angle has the best seal performance;it has guiding signifi-cance for optimal design of seal.