Study On Flow Resistance And Separation Efficiency Of Axial Ventilator In Inclined Ventilation Holes

The ventilator is separated from the oil and gas mixture composed of sealed air and oil in the aeroengine lubrication system,and its flow resistance and separation efficiency have a key impact on the normal operation of the sealing system and oil consumption.In this paper,a new type of ventilation system with inclined ventilation holes is proposed,and the performance of axial ventilation system with different inclined ventilation holes is studied.In order to further analyze the law and mechanism of separation efficiency affected by the flow parameters in the ventilation and the ventilation pipe,and to provide the theoretical base and reference for the optimization of the ventilator.In this paper,the separation efficiency and flow resistance of axial ventilator with inclined ventilation holes were studied by numerical simulation taking advantage of computational fluid dynamics.A numerical calculation two-phase flow model of oil-gas in ventilator built on the theory of Euler-Lagrange multiphase was established for the dispersion of oil-gas mixture in ventilator.The dispersion phase model（DPM）was used to calculate the trajectory of the droplets inner axial ventilator,and the Reynolds stress turbulence model was adapt to calculate the velocity of Reynolds time-averaged for the continuous phase in the axial ventilator.In this paper,9 structural schemes with 3 kinds of inclined angles of ventilation holes and different combinations of cross-section length,width and eccentricity were calculated,and the law of separation efficiency and flow resistance were analyzed,and compared with the original structure,the optimum inclined angle of the ventilation holes was obtained.The numerical calculation model is certified by comparing the result of calculation with the experiment.The relative deviation between the calculated and the measured is 0.62%,the discussion tells that the separation efficiency and flow resistance calculated by the numerical simulation model are reliable.The conclusion show that the maximum of separation efficiency is obtained when the inclined angle of the ventilation is 60,and the separation efficiency is positively correlated with the centripetal acceleration,velocity moment and turbulence intensity in the cavity of the ventilator.The ventilation holes of the improved structure scheme is inclined,and the oil and gas separation function of the inner cavity and the ventilation pipe of the improved structure scheme is brought into play more effectively.