自振射流喷嘴振荡腔内信号检测方法  

A new detection method of fluid pulsation inside the oscillation cavity of a self-resonating water jet nozzle

作　　者：韩健[1] 柳靖[1] 汪晖[1] 马飞[1] 蔡腾飞[1] 

机构地区：[1]北京科技大学机械工程学院,北京100083

出　　处：《工程科学学报》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)

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.

关 键 词：水射流 喷嘴 振荡腔 涡量 扰动 信号分析 

分 类 号：TP69[自动化与计算机技术—控制理论与控制工程]