液体雾化状态的声发射检测

为检测液体雾化状态,基于声发射检测技术,通过采集雾化液体撞击挡板产生的声发射信号,结合功率谱分析、小波分析和重标极差分析,得到雾化液体撞击挡板产生声信号的机理和特征,获得表征液体雾化状态的特征声信号尺度(J1尺度)。根据特征信号尺度能量分率与液体雾化状态间的规律性变化关系,提出雾化质量的判断方法,即液体雾化质量随特征信号尺度能量分率的增大而提高,当特征信号尺度能量分率快速上升时,液体进入充分雾化状态。判断方法得到照相法的验证。利用声发射检测发现液体雾化质量随轴向距离增大而提高,与事实相符。由此获得一种快速、实时、便捷和安全的液体雾化状态检测方法,其可用于雾化机理研究、喷嘴设计选型和工业生产监控。

Detection of Liquid Atomization Status Using Acoustic Emission Method

In order to detect the liquid atomization status,acoustic emission(AE) signals which originated from the impact of liquid spray on the plate are collected by using AE measurement.The generating mechanism and character of the AE signals,and the characteristic scale(J1) of AE signals which represented the status of liquid atomization are obtained by using power spectrum analysis,wavelet transform and rescaled range(R/S) analysis.Since the energy fraction of AE signals in J1 scale changed regularly with the atomization status,a new method for judging the liquid atomization performance is presented.The liquid was better atomized with the increase of AE energy fraction in J1 scale.When the AE energy fraction in J1 scale increased rapidly,the liquid spray is sufficiently atomized.This method is verified by the photos of liquid spray.Based on the variation of the AE energy fraction in J1 scale,it is found that the atomization performance became better along the axial direction of the spray bundle.It is concluded that multi-scale analysis of acoustic signals is feasible for detecting the liquid atomization status which have the merit of being sensitive,convenient,real-time and safe.