单级轴流压气机纯音噪声实验与数值分析

Experimental and numerical analysis on tonal noise of single-stage axial compressor

为了探索转/静干涉纯音噪声与静子前缘上洗速度之间的对应关系,使用已发展的风扇纯音噪声混合预测方法对一台单级、低速压气机实验台(TA36)节流过程中的转/静干涉纯音噪声进行了预测,并与实验结果进行了对比验证。为了准确获取作为转/静干涉纯音噪声声源的静子叶片表面非定常压力脉动,首先比较了不同计算网格与时间步长设置对叶片表面非定常压力脉动计算的影响。随后,比较了静子叶片来流上洗速度和纯音噪声随质量流量的变化规律。研究表明:设计转速下,静子前缘70%、80%以及90%叶高的3阶叶片通过频率处的上洗速度幅值随质量流量的变化规律与混合预测方法估计的进气管道壁面声压级的变化趋势一致,并且与实验测量值的变化规律也保持了良好的一致性。此外,管道外远场声压级指向性的结果也表明:该实验台远场声辐射具有明显的指向性,并且不会随着节流过程产生明显的变化。

To investigate the correlation between the tonal noise generated by rotor/stator interaction and the incoming upwash velocity of the stator,the tonal noise of a single-stage,low-speed axial compressor test rig(TA36)in a throttling process was studied by a well-developed inhouse hybrid noise prediction method.In order to accurately capture the source of the tonal noise,i.e.,unsteady pressure fluctuation on the surface of the stator blade,the effects of the simulation grid and time-step size on the prediction of the unsteady pressure fluctuation were discussed firstly.Then,the variations of upwash velocity and tonal noise in the throttling process were compared.The result showed that at the third blade passing frequency(BPF)of the design speed,the amplitude variation of the incoming upwash velocity on the 70%,80%,and 90%span of the stator was consistent with the sound pressure level predicted by the hybrid method,and kept good consistency with the experimental measurements.In addition,the sound radiation in the far field demonstrated significant directivity while the directivity did not change significantly with the mass flow rate.