柴油机表面辐射噪声源识别研究
Study on Surface Radiation Noise Source Identification of Diesel Engine

以某单缸柴油机为研究对象，建立近场声压与表面振速联合信息法对该柴油机进行了表面辐射噪声源识别的研究。首先，利用近场声压阵面扫描快速定位了标定工况下主要辐射表面的主要辐射部件；再基于平板结构的辐射模型，研究分析了主要辐射部件的声辐射能力；然后，在综合考虑声辐射系数影响因素基础上，识别分析了主要辐射部件结构表面噪声的辐射特性，与传统方法相比提高了识别精度；再结合隔声法深入地识别了主要辐射部件结构噪声中的主要噪声源；最后，对建立方法识别结果进行了降噪试验验证。该识别方法可为明确柴油机降噪目标以及结构低噪声设计目标提供理论指导。
In this paper, an experimental study on the surface radiation noise source identification of the diesel engine was carried out, by the proposed joint information method of near field sound pressure and surface velocity. A single cylinder diesel engine was used in the experiment. Firstly, main radiating components of main radiating surface were identified quickly by near field scan method under engine calibration conditions; the radiation capability of main radiating components was studied based on plate radiation model. Secondly, on the basis of considering influence factor of the sound radiation coefficient, radiation characteristics of structural surface noise for main radiating components were analyzed, compared with the traditional method, identification accuracy was improved; the main noise source from structural noise of main radiating components was further identified with sound insulation. Lastly, recognition results got by the proposed method were verified through noise abatement test. This identification method can provide theoretical guidance for defining goals of the diesel engine noise abatement and low noise structure design