摘要
测量了 3毫米口径轴对称收缩喷嘴射流冲击大平板产生的噪声随冲击距离变化的特性。发现远场噪声随冲击距离的变化呈锯齿状 ,射流上游的噪声频谱上有粗缓、跨较宽频带的尖峰。根据不同唇厚喷嘴的实验对比 ,判断这些现象跟反馈有关 ,称为反馈噪声 ,而且正是反馈噪声与湍流噪声的相互作用 。
The characteristics of the far-field noise of impinging jet with 3-millimeter diameter axisymmetric convergent nozzle under the condition of variable nozzle-to-plate distance,and their methanism were investigated experimentally.It is found that the far-field noise intensity of the 3 mm nozzle impinging jet has a saw-tooth behavior with the variation of nozzle-to-plate distance,and there are some chunky broadband peaks on the narrow-band noise spectrum,and these peaks exist only on the upstream of the jet.According to the consideration of key factors responsible for the feedback loop and results of the experiments performed to detect the effect of nozzle exit lip thickness on these new phenomena,the feedback mechanism is suggested to be responsible for these phenomena,and the associated noise is defined as weak feedback noise.The interaction of the turbulent noise and weak feedback noise induces the saw-tooth behavior of the total noise intensity with the variation of nozzle-to-plate distance.
出处
《振动与冲击》
EI
CSCD
北大核心
2003年第4期36-39,48,共5页
Journal of Vibration and Shock
基金
国家自然科学基金项目 (1 990 2 0 0 9)
