Research on Performance Prediction Model of Impeller-Type Breather

Abstract

To investigate the characteristics of separation and resistance of an impeller-type breather in an aeroengine lubrication system, orthogonal test design is used in calculation of the operating condition. Also, phase coupling of the RNG(Renormalization Group) k − ε model and the DPM model (Discrete Phase Model) is used in calculating the selected operating condition. Through analysis of the results, combined with dimensional analysis, it shows the significance of various influencing factors and the optimal level. Based on this, a general formed dimensionless group equation is established for comprehensive separation efficiency, breather separation efficiency, and ventilation resistance. Also, through the least squares method, the performance prediction model of the breather is obtained considering five operating conditions and six structural parameters. The theoretical calculation of separation efficiency and ventilation resistance of an impeller-type breather can be performed. The results show that: the main factors affecting the separation efficiency are the rotating speed and the number of impeller blades; the main factors affecting the ventilation resistance are the ventilation rate and the diameter of the vent hole; the variation trends of the calculated values of the performance prediction model and the experimental values are consistent. The mean error of the comprehensive separation efficiency is 0.97% and the mean error of the ventilation resistance is 11.73%. The calculated values and the experimental values remain consistent, which proves that this performance prediction model can provide references to the assessment and the design of an impeller breather.