柴油机噪声源的识别及降噪研究

采用部分缸熄火的方法对机械噪声和燃烧噪声进行了分离，在表面辐射噪声源的识别上，通过表面振动识别，找到了噪声辐射的主要部件。针对现有柴油机的燃烧状况，对供油提前角进行了调整，降低了燃烧噪声。通过加装扭振减振器，使得曲轴扭振明显减小。改进油底壳对柴油机辐射噪声起到了很好的抑制作用。

Noise Source Identification and Noise Reduction for Diesel Engine

Partial cylinder misfiring method is used to separate machinery noise and combustion noise. The radiating noise sources are identified with near field scan technique and the main part of surface radiating noise can be found. By modifying the advanced angle of fuel supply, combustion noise is reduced. In order to decrease torsional vibration of the crankshaft, a new-designed torsional vibration damper is applied to the free-end of crankshaft. By altering the shape of oil pan, radiation noise can also be suppressed to a certain extent.