CAJ | 학술논문

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。
위료획취분취진탕강내적압력맥동신호，제출일충신적검측방법。수선분석자진사류적특성，설계료산생자진사류적분취결구；결합계산류체동역학분석분취강내동압분포，학정측압점위치；운용류체망락이론분석자진사류적빈솔특성，재차기출상학정용우실험적미형고향응압력전감기；고필도강내진탕신호적비평은성，채용희이백특-황변환( HHT)신호분석방법。실험결과표명，강내진탕신호주요집중우40~60 Hz、110~150 Hz화200~310 Hz삼개빈대，차조성빈솔성분소대응적폭치차이명현；거리분취출구교근처，자진신호진폭교대，빈대착。
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.