Abstract: To study the leakage characteristic of finger seal under different differential pressure and rotational speed, a numerical calculation model with CFD porous media was built in this paper. The leakage characteristic of finger seal used in a specific aero engine was analyzed. To verify the numerical calculation model, an experimental study of leakage characteristic of finger seal under simulating certain differential pressure and rotational speed was developed. To study variations of porous media parameters caused by differential pressure and centrifugal expansion of rotor, the calculation method was analyzed based on the experimental results, correction factor C_k for differential pressure and correction factor k for centrifugal expansion were raised and validated. The results show that, without introducing correction factor C_k for differential pressure and correction factor k for centrifugal expansion, calculated leakage characteristic of finger seal deviate from the experimental values with the increase of differential pressure and rotational speed. While introducing correction factor C_k for differential pressure and correction factor k for centrifugal expansion, the calculated results are in agreement with the experimental results, and do not deviate from the experimental results with the increase of differential pressure and rotational speed, the maximum deviation is less than 11%, and the average deviation is less than 6%.

Key words: Aero engine;Finger seal;Leakage characteristic;Numerical calculation;Experiment

摘要： 为了研究不同压差和转速下指尖密封的泄漏特性，建立了CFD多孔介质数值计算模型，计算分析了某型航空发动机指尖密封泄漏特性。为有效验证数值计算模型的有效性，进行了一定压差、转速工况下指尖密封泄漏特性试验。针对压差和转子离心膨胀导致的多孔介质参数改变，根据试验结果对计算方法进行了分析，引入了压差修正系数C_k和离心膨胀修正系数k，并对修正系数进行了确定及验证。结果表明，未引入压差修正系数C_k和离心膨胀修正系数k时，计算得到的指尖密封泄漏特性与试验值会随着压差和转速的增加而偏离；引入压差修正系数C_k和离心膨胀修正系数k后，计算结果与试验值一致，未随着压差和转速的增加而偏离，最大偏差小于11%，平均偏差小于6%。

关键词: 航空发动机;指尖密封;泄漏特性;数值计算;试验