船用压气机气动噪声源频谱特性数值研究

以某型号大型船用涡轮增压器压气机为研究对象,以CFD软件为平台,利用具有k-ε双方程湍流模型的NS方程计算了压气机的三维黏性非定常流场特性。采用Ffowcs Williams-Hawkings方程(简称FW-H方程)对压气机的离散噪声进行了分析,并与经验公式进行了比较。深入研究了不同转速、流量对压气机气动噪声的影响。分析表明,叶轮内气动噪声水平较高,是主要噪声源;转速对于离散噪声影响较大,转速增加一倍,声压级上升约14dB;同一转速下,流量的降低将导致噪声幅值增加,但相对于转速变化其影响较小。

Numerical Investigation of Spectral Characteristics of Aerodynamic Noise Source for Marine Turbocharger Compressor

The unsteady three-dimensional viscous flow field of a large marine turbocharger compressor was simulated by Navier– Stokes equations with the two-equation( k-ε) turbulence model based on the CFD software. The discrete noise of the compressor was analyzed by the Ffowcs Williams-Hawkings formulation( FW-H for short),and the results were compared with the experimental formula. The effect of the speed and the flow rate on the aerodynamic noise was further studied. The numerical results indicate that the aerodynamic noise of the impeller is dominant; the rotating speed of the impeller has a great influence on the discrete noise,the noise increased by about 14 dB when the rotating speed was doubled; the noise will increase when the flow rate reduces at the same speed,but the effect is much less than the speed of the impeller.