模化设计对离心压气机气动噪声的影响

采用数值计算方法研究了模化设计对压气机气动噪声的影响，三维流场计算结果表明模化设计压气机与原始机型满足相似准则，整级性能参数误差在2%以内；流场结构的分析进一步证实了模化机型与原始机型流场相似。基于非定常雷诺平均方法和声学边界元方法的混合气动声学方法对模化前后的压气机气动噪声进行了数值预测，结果表明:压气机气动噪声主要由离散单音噪声和宽频噪声组成，且离散单音噪声占主导。模化机型总声压级随着模化比减小逐渐减小，相比于原始机型，模化机型离散单音噪声峰值仅略有降低，而宽频噪声大幅提高。压气机气动噪声在进气管口有明显指向性，模化机型声压幅值和指向性较原始机型降低，且变化趋势与模化比成正比。 

Effects of modeling design on centrifugal compressor aerodynamic noise

The effects of modeling design on compressor aerodynamic noise were studied by numerical method, the calculation results of the three-dimensional flow field indicated that the modeling designed compressors and the original model satisfied the similarity criterion, and the relative error of the global performance parameters were less than 2%. The analysis of compressor flow structure further confirmed that the flow field of the modeling designed compressor was similar to that of the original model. The compressor aerodynamic noise was investigated by a hybrid computational aero-acoustic method, which combined unsteady Reynolds averaged Navier-Stokes equations and boundary element method. The results showed that the compressor aerodynamic noise was mainly composed of discrete tones and broadband noise, and the discrete tones dominated in the spectrum. The total sound pressure level of modeling designed compressor gradually reduced with the decreasing scale factor, the peaks of modeling designed compressor discrete tones were slightly lower than those of the original model, but the broadband noise was greatly enlarged. Compressor aerodynamic noise showed obvious acoustic directivity in the inlet duct nozzle, the sound pressure amplitude and directivity of the modeling designed compressor was weaker than the original model, and the trend was proportional to the scale factor.