考虑表面粗糙度的液膜密封稳态特性分析

Analysis of Steady Characteristics of Liquid Film Seal Considering Surface Roughness

为了研究表面粗糙度对液膜密封性能的影响,考虑建立表面粗糙度的螺旋槽液膜密封数学模型,采用有限元法求解稳态Reynolds方程,进而分析了表面特性及综合粗糙度标准差对液膜密封开启力、刚度及泄漏量的影响。结果表明:表面特性小于1时,密封开启力、刚度小于密封面光滑时的值,泄漏量大于密封面光滑时的值,且综合粗糙度标准差越大,开启力、刚度越小,泄漏量越大;表面特性大于1时,密封开启力、刚度大于密封面光滑时的值,泄漏量小于密封面光滑时的值,且综合粗糙度标准差越大,开启力、刚度越大,泄漏量越小;随着表面特性的增加,密封开启力、刚度均逐渐增加,而泄漏量逐渐减小,因此表面特性大于1时,密封性能较优。

A mathematical model of spiral groove liquid film seal considering surface roughness was established for studying the effect of surface roughness on the sealing performance of liquid film seal.The steady Reynolds equation was solved by means of finite element method,and then the influence of surface characteristic and standard deviations of combined roughness on pening force,stiffness and leakage of liquid film seal were analyzed.Results indicate that when surface characteristic is less than 1,opening force and stiffness are less than the values of smooth surface,and leakage is greater than the value of smooth surface.Meanwhile,opening force and stiffness decrease with the increase of standard deviations of combined roughness,but leakage increases.When surface characteristic is greater than 1,opening force and stiffness are greater than the values of smooth surface,and leakage is less than the value of smooth surface.Also,opening force and stiffness increase with the increase of standard deviations of combined roughness,but leakage decreases.Opening force and stiffness are increased with the increase of surface characteristic,leakage decreases gradually,however.Therefore,the sealing performance is better when surface characteristic is greater than 1.