发动机燃烧噪声与机械噪声对整机噪声贡献度的实验研究

Experimental Analysis of Combustion Noise and Mechanical Noise Contribution for Motorcycle Engine

以某CG125型摩托车发动机为研究对象,依据噪声叠加的原理,通过实验研究的方法对其燃烧噪声和机械噪声进行了分离。依据工程法测定摩托车发动机噪声平均声压级的方法,计算出了平均声压级及燃烧噪声和机械噪声对整机噪声声功率的贡献度。研究结果表明发动机转速不变时,随着发动机负荷的增加,燃烧噪声的贡献度逐渐增加;而当发动机负荷不变时,随着发动机转速的增加,机械噪声的贡献度迅速增加。频谱分析的结果表明,随着负荷的增加,燃烧噪声中1000Hz以下的低频成份有明显的增加。

This thesis summarizes the experimental method of separation of mechanical and combustion noise of a 125 style motorcycle engine and analyses the contribution of them each. It also gives the change rule of both of them under certain loads or rotating speed. By means of spectrum analysis, it brings forward the frequency components of each kind of noise. This is the foundation for the engine noise reduction.