柴油机空气动力噪声分析及控制方法研究

Analysis of the Aerodynamic Noise from Diesel Engines and Research on its Control

柴油机因为具有经济性和排放性等优点而受到广泛应用,但同时它也会产生很大的噪声。讨论了柴油机的噪声危害,按辐射方式对柴油机噪声进行了分类,并重点分析了空气动力噪声,分别从进气、排气和风扇等方面介绍了柴油机空气动力噪声的产生机理和控制方法。研究表明,进气噪声和排气噪声的控制大多采用添加消声器的方法,风扇噪声的控制大多从风扇的结构参数和布置形式着手考虑。介绍了CFD建模及仿真分析噪声的思路方法,为后续优化设计打下基础。但在降低噪声的同时,必须保证风扇的其他性能参数达到所需要求。

Diesel engines are widely used for their advantages of economy and emission performance, yet they produce much noise. Therefore, the noise hazard is discussed. The noise from diesel engines is classified into several categories by its radiation mode. Special emphasis is placed on the analysis of the aerodynamic noise, its formation mechanism, and ways to control it. The analysis is carried out in the following three aspects respectively： the inlet, outlet and the fans. Research shows that the noise produced by the inlet and outlet can be controlled mostly by installing mufflers; and noise from the fans can be controlled by adjusting the structure parameters and their arrangement. Then the general ideas of establishing CFD model and simulation analysis of the noises are pro- posed, which lay foundation for the subsequent optimized design. It is emphasized that when the noise is reduced, other perform- ance parameters of the fans must meet the requirement.