渗透度对锯齿形尾缘喷嘴气动声学影响研究

在低马赫数条件下（Ma=0.12），采用时间分辨TR-PIV以及远场噪声测量方法，对不同渗透度锯齿形尾缘喷嘴的气动声学特性进行实验研究。流场测量结果表明，锯齿形尾缘喷嘴缩短势核长度，增加势核内气流和周围环境气流的掺混，随渗透度的增加该趋势得到增强。远场声学测量结果表明，随着渗透度增加，锯齿形尾缘喷嘴对于噪声低频降低和高频增加的幅度都有所增强。低渗透度的锯齿形尾缘喷嘴有效降低噪声总声压级，在150°时总声压级降低达到1.3 dB，研究对于降低工厂排空噪声有现实意义。

Effect of Penetration on Aerodynamic Acoustic Characteristics of Chevron Nozzle

Using TR-PIV technique and far-field measurement method, the aerodynamic acoustic characteristics of chevron nozzles with different penetrations have been studied at the Mach number Ma=0.12. Flow field results show that the chevron nozzles can reduce the potential core length and increase the mixing of the air flows in the core with the environment. With the penetration being higher, this tendency is increased. It is found that the chevron nozzles with high penetration can reduce low frequency noise, but increases high frequency noise; while the chevron nozzles with low penetration can reduce the global sound pressure level of the noise effectively. At aft angle of 150°, the chevron nozzle with low penetration can bring noise suppression by 1.3 dB. This work is of practical significance for jet noise control of factories.