油气润滑系统水平管路中环状流油膜扰动波特性

摘要

Interfacial speeds of air and oil of annular flow in straight pipe of oil-air lubrication system were defined,transient time values of oil film thickness under different air and oil interfacial speed were calculated by simulation,the autocorrelation function,cross-correlation function and power spectral density of disturbance wave of oil film were studied by time-frequency method,the disturbance wave characteristics of air-oil annular flow in oil-air lubrication system were analyzed.The results show that the characteristics of autocorrelation function,cross-correlation function and power spectral density function of disturbance wave signal of oil film under different interfacial speed of air and oil are different.At constant interfacial speed of oil,with the increasing of interfacial speed of air,the average wave speed and wave length of disturbance wave are increased and the mean frequency is decreased,the energy carried by the disturbance wave in the annular flow film in the low frequency region is reduced.At constant interfacial speed of air,with the increasing of interfacial speed of oil,the average wave speed,wave length and mean frequency of the disturbance wave are all decreased,the energy carried by the disturbance wave is mainly in the low frequency region,and the energy fluctuation is remarkable in the low frequency region.%定义油气润滑系统水平管环状流的气液折算速度,通过仿真提取油气润滑系统水平管中不同气液折算速度下不同位置瞬态油膜厚度随时间的变化值,运用时频分析方法研究环状流油膜扰动波信号的自相关函数、互相关函数以及功率谱密度函数,分析油气润滑系统中气液环状流油膜扰动波特性.结果表明,不同气液折算速度下油气润滑系统环状流油膜扰动波信号的自相关、互相关函数与功率谱密度函数具有不同的特征;液相折算速度不变时,随着气相速度增大,扰动波的平均波速和波长增大,平均频率减小,低频区环状流液膜扰动波携带的能量减少;气相折算速度不变时,随着液相速度增大,扰动波的平均波速和波长及平均频率均减小,扰动波携带的能量主要集中在低频区,且在低频区能量波动显著.