摘要
为研究低马赫数条件下射流冲击圆锥形障碍物的气动声学特性,针对4个冲击距离下的射流声场进行了远场实验测量,并基于大涡模拟进行了数值模拟计算,结果显示声场测量与数值结果吻合较好。从数值模拟捕捉到的冲击射流涡结构产生、演化以及耗散的变化现象,分析了冲击距离与远场声压之间的影响因素及涡变化与声源分布关系,发现影响冲击射流的主要噪声源与冲击距离具有很强的相关性。研究表明:障碍物位于10D_e位置处时所接收到的声压级最大,影响冲击射流的主要噪声源为旋涡脱落引起的具有宽频带特性的偶极子噪声源;当冲击距离较远时,主要声源为具有低频特性的自由射流段涡环配对产生的四极子源。
In order to study acoustic characteristics of jet impinging on the conical obstacle at low Mach number,the Large Eddy Simulation（LES） method were used for modeling impinging jet in different impinging distance.The noise characteristics and trend of impinging jet were experimentally and theoretically investigated,the model was proved to be correct by comparing with the experiment.Based on the formation,development and structure change of the vortex captured by simulation,the influence between impinging distance and far-field sound pressure and the relationship between vortex change and sound source distribution were investigated.It is found that impinging distance determines the dominant acoustic sources due to jet impingement.It is revealed from the numerical analysis that the acoustic level received at 10De is the highest,dipole source due to vortex shedding is the dominant acoustic source;when jet is far to the obstacle,quadrupole source in the nature of low-frequency due to free jet is the dominant acoustic source.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2016年第6期1212-1217,共6页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助项目(No.51376077)
关键词
冲击射流
圆锥障碍物
气动声学
数值模拟
impingement jet
conical obstacle
aerodynamic acoustics
numerical simulation
