Leakage of lubricating oil from carbon seal system of bearing chamber caused by insufficient seal pressure from com-pressor and excessive oil supply pressure of bearing chamber has an important effect on the operational stability of aero-engine. Based on air-bleeding oil-sealing mode, an experimental device was designed and built to simulate structure and working environment of the carbon seal system in bearing chamber of an actual aero-engine. Evolution process of oil leakage flow was visually observed. Effects of rotor speed and oil temperature on the critical oil-sealing pressure differ-ence were experimentally studied. Leakage flow mechanism of oil through the carbon seal system in bearing chamber was revealed. Results show that: With gradual decrease of sealing pressure difference, the lubricating oil leaked initially from bottom of carbon seal ring, and in turn underwent four processes, i.e., infiltration and backflow, increased infiltration, droplet-like leakage, and fluid-like leakage. Value of sealing pressure difference corresponding to that the droplet-like leakage occurred was considered as critical oil-sealing pressure difference of carbon seal system in bearing chamber. As rotor speed decreased from 12500r/min to 4000r/min, lower centrifugal force of oil in respond to lower rotor speed made seal clearance to be filled with more oil, resulting in the increasing critical oil-sealing pressure difference from 4.1 kPa to 29.28 kPa. With decreasing lubricating oil temperature from 121℃ to 40℃ progressively, density and dynamic viscosity of the oil increased, gravity and viscous acting on the oil increased, accumulation of the oil in seal clearance also increased, which further led to increase of the pressure difference from 4.96 kPa to 29.28 kPa.
[1]黎林林, 谢光华.某型号涡喷发动机滑油系统设计[J].推进技术, 2001, 22(6):493-495
[2]LI L L, XIE G H.Oil system design of a certain turbo-jet engine[J].Journal of Propulsion Technology, 2001, 22(6):493-495
[3]FLOUROS M.The impact of oil and sealing air flow,chamber pressure,rotor speed,and axial load on the power consumption in an aeroengine bearing cham-ber[J].Journal of Engineering for Gas Turbines and Power, 2005, 127(1):182-186
[4]航空发动机设计手册总编委会.航空发动机设计手册:传动及润滑系统[M]. 北京:航空工业出版社, 2002, 167-186.
[5]Chief Editorial Committee of Aviation Engine Design Manual.Aviation engine design manual: Transmission and lubrication systems[M]. Beijing：Aviation Indus-try Press, 2002, 167-186 (in Chinese).
[6]MICHAELIS S.Oil bearing seals and aircraft cabin air contamination[J].Sealing Technology, 2016, 2016(4):7-10
[7]REN G Z, LI Y P, ZHAO H, et al.Research on Oil-Gas Two-Phase Flow Characteristics and Improvement of Aero-Engine Bearing Chamber[J].Lubricants, 2023, 11(9):360-360
[8]孙恒超, 陈国定, 王莉娜, 等.轴承腔油滴含率及油滴相与空气能量传递分析[J].航空学报, 2016, 37(3):1060-1073
[9]SUN H C, CHEN G D, WANG T.Oil Droplets Frac-tions and Oil DropletsAir Energy Transfer Analysis in Bearing Chamber[J].Acta Aeronautica et Astronautica Sinica, 2016, 37(3):1060-1073
[10]李炎军, 杨富, 刘振侠, 等.轴承腔油气两相介质流动与热分析[J].航空动力学报, 2021, 36(3):606-615
[11]LI Y J, YANG F, LIU Z X, et al.Flow and thermal analysis of oil air two-phase medium in bearing cham-ber[J].Journal of Aerospace Power, 2021, 36(3):606-615
[12]LI S B, LI C X, WANG W.Simulation of unsteady flows of oilgas in the ventless bearing chamber of an aero-engine[J].Aerospace, 2022, 9(4):211-211
[13]LU P, YE Q H, FANG L L, et al.Research on the air–oil two-phase flow regime in an aeroengine bearing chamber based on Hilbert–Huang transform[J].Pro-ceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2022, 236(1):24-32
[14]NICOLI A, JOHNSON K, JEFFERSON-LOVEDAY R.Simulation of a simplified aeroengine bearing chamber using a fully coupled two-way Eulerian thin filmdiscrete phase approach part I: Film behavior near the bearing[J].Journal of Engineering for Gas Turbines and Power, 2021, 143(10):101015-101015
[15]NICOLI A, JOHNSON K, JEFFERSON-LOVEDAY R.Simulation of a simplified aeroengine bearing chamber using a fully coupled two-way Eulerian thin filmdiscrete phase approach part II: Droplet behavior in the chamber[J].Journal of Engineering for Gas Tur-bines and Power, 2021, 143(10):101016-101016
[16]王莉娜, 陈国定, 孙恒超.轴承腔油滴沉积特性及油膜流动特征分析[J].航空学报, 2016, 37(10):3159-3169
[17]WANG L N, CHEN G D, SUN H C.Characteristics analysis of oil droplet deposition and oil film flow in a bearing cavity[J].Acta Aeronautica et Astronautica Sinica, 2016, 37(10):3159-3169
[18]CHEN G D, SUN H C, WANG J.Research into con-figuration and flow of wall oil film in bearing chamber based on droplet size distribution[J].Chinese Journal of Aeronautics, 2011, 24(3):355-362
[19]王轶泽, 刘红彬, 孟永钢.高速圆柱滚子轴承环下润滑热场特性[J].航空动力学报, 2024, 39(5):249-257
[20]WANG Y Z, LIU H B, MENG Y G.Study on thermal field characteristics of high speed cylindrical roller bearing under ring lubrication[J].Journal of Aerospace Power, 2024, 39(5):249-257
[21]丁少鹏, 白少先.气体润滑环瓣式浮动环密封高速特性[J].润滑与密封, 2016, 41(7):43-47
[22]DING S P, BAI S X.Behavior of a gas lubricated split floating ring seal operating at high speed[J].Lubrication Engineering, 2016, 41(7):43-47
[23]仰宏伟, 白少先.环瓣式浮环密封表面瑞利台阶型槽气体润滑动压特性[J].推进技术, 2022, 43(2):148-154
[24]YANG H W, BAI S X.Gas hydrodynamic lubrication performance of split floating ring seals with Rayleigh step Grooves[J].Journal of Propulsion Technology, 2022, 43(2):148-154
[25]任国哲, 李延鹏, 孙丹, 等.动压型分瓣式浮环密封泄漏特性流固热耦合数值研究[J/OL]. 航空动力学报, 1-11[2024-09-25]. https://doi.org/10.13224/j.cnki.jasp.20230261.
[26]REN G Z, LI Y P, SUN D, et al.Numerical study on leakage characteristics of dynamic pressure split float-ing ring seal with fluid-solid coupling[J/OL]. Journal of Aerospace Power, 1-11[2024-09-25]. https://doi.org/10.13224/j.cnki.jasp.20230261.
[27]运睿德, 陈志英, 刘勇, 等.周向弹簧力分布对圆周密封装置密封性能的影响[J].推进技术, 2021, 42(6):1361-1371
[28]YUN R D, CHEN Z Y, LIU Y, et al.Effects of circum-ferential spring force distribution on sealing perfor-mance of circumferential seal[J].Journal of Propul-sion Technology, 2021, 42(6):1361-1371
[29]WANG S, SUN D, YANG Z M, et al.Investigation of static and rotordynamic characteristics of the segment-ed annular seals based on the differential quadrature method[J].Tribology International, 2024, 196:109657-109657
[30]LI G Q, ZHANG S, KANG Z, et al.Leakage and wear characteristics of carbon seals for aero-engines[J].Chinese Journal of Aeronautics, 2022, 35(11):389-400
[31]郭金道, 赵欢, 王平, 等.基于引气封油方式的轴承腔密封间隙油气两相泄漏流动特性数值与试验研究[J].机械工程学报, 2024, 60(3):214-225
[32]GUO J D, ZHAO H, WANG P, et al.Numerical and experimental study on oil-air two-phase leakage flow characteristics based on air-bleeding oil-sealing mode in seal clearance of bearing cavity[J].Journal of Me-chanical Engineering, 2024, 60(3):214-225
[33]何彬, 马正军, 李卓, 等.某型燃气轮机轴承腔压力异常分析及改进[J].热能动力工程, 2021, 36(10):187-192
[34]HE B, MA Z J, LI Z, et al.Analysis and improvement of abnormal pressure in bearing cavity of a gas tur-bine[J].Journal of Engineering for Thermal Energy and Power, 2021, 36(10):187-192
CJA