摘要
为了获取喷嘴振荡腔内的压力脉动信号,提出一种新的检测方法.首先分析自振射流的特性,设计了产生自振射流的喷嘴结构;结合计算流体动力学分析喷嘴腔内动压分布,确定测压点位置;运用流体网络理论分析自振射流的频率特性,在此基础上确定用于实验的微型高响应压力传感器;考虑到腔内振荡信号的非平稳性,采用希尔伯特-黄变换(HHT)信号分析方法.实验结果表明,腔内振荡信号主要集中于40~60 Hz、110~150 Hz和200~310 Hz三个频带,且组成频率成分所对应的幅值差异明显;距离喷嘴出口较近处,自振信号振幅较大,频带窄.
To obtain characteristic pressure signals in the cavity of a self-resonating water jet nozzle, a detection system was built by using micro high-responsive pressure sensors. The characteristics of self-resonating water jet were studied and the nozzle’ s structure was designed. The sensors’ layout was determined based on computational fluid dynamics ( CFD) simulation results, and the respon-sive frequency of the sensors was determined according to theoretical calculations of the nozzle’ s self-excited oscillation frequency. The Hilbert-Huang transform was used due to the nonstationarity of pressure signals in the cavity. It is found that the pressure oscillation signals are focused on the frequency band of 40-60 Hz, 110-150 Hz and 200-310 Hz, and each frequency has different fluctuation am-plitudes. Pressure signals near the water outlet reach larger amplitudes with narrow bandwidth.
出处
《工程科学学报》
EI
CAS
CSCD
北大核心
2015年第9期1191-1197,共7页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(51274021)
关键词
水射流
喷嘴
振荡腔
涡量
扰动
信号分析
water jet
nozzles
oscillation cavity
vorticity
disturbance
signal analysis