CFM56系列发动机篦齿结构多目标参数优化分析

Multi Objective Parameter Optimization Analysis of Labyrinth Seal of CFM56 Series Engine

为解决CFM56系列发动机在低转速情况下滑油腔内润滑油的渗漏问题,运用VOF两相流理论对其篦齿封严进行数值模拟,分析篦齿的齿数、齿距、篦齿间隙、篦齿齿高、齿顶宽以及齿形角等结构参数对润滑油渗漏量的影响。结果表明:润滑油的渗漏量随齿顶间隙的增加而明显增大,当齿顶间隙在0.3~0.4 mm时,渗漏量增加趋势较为明显;齿距对渗漏量的影响较小,随齿距增大渗漏量小幅增大;渗漏量随齿形角的增大而明显降低,尤其在齿形角小于90°时;随齿顶宽度的增大渗漏量先增大后减小;随齿数的增大渗漏量降低,齿数为2~4时渗漏量降低明显,齿数高于4后变化趋于缓和。以篦齿渗漏量最小为目标,采用响应曲面法进行多目标参数优化,优化后润滑油渗漏下降了87.5%。

In order to solve the problem of oil leakage in the lubricating oil chamber of CFM56 series engine at low speed,the numerical simulation of labyrinth seal was carried out by using volume of fluid(VOF)two-phase flow theory.The effects of structural parameters such as tooth number,tooth pitch,tip clearance,tooth height,tooth tip width and tooth angle on the leakage of lubricating oil were analyzed.The results show that the leakage of lubricating oil increases obviously with the increase of tooth tip clearance.When the tooth top clearance is from 0.3 mm to 0.4 mm,the increasing trend of leakage is more obvious.The tooth pitch has little effect on the leakage,and the leakage of lubricating oil increases slightly with the increase of tooth pitch.The leakage decreases obviously with the increase of tooth angle,especially when the tooth angle is less than 90°.The leakage first increases and then decreases with the increase of tooth tip width.The leakage decreases with the increase of the tooth number.When the tooth number is 2 to 4,the leakage decreases obviously,and the change tends to stable when the tooth number is higher than 4.Taking the minimum leakage of labyrinth seal as the goal,the response surface method was used to optimize the multi-objective parameters.After optimization,the lubricating oil leakage is reduced by 87.5%.