统计频率的传递路径分析在客车降噪中的应用

Transfer path analysis with statistics of frequencies on bus noise reduction

整体降低客车车内噪声水平的需求日益迫切.车内噪声场的分布具有多源性、复杂性等特点.通过把车内空间划分成若干部分并考虑多个噪声源在车内整个空间的噪声传递,建立了多条噪声传递路径;通过对不同的工况下同一噪声传递路径的测量分析,发现了传递函数的峰值存在频率偏移.对此提出了在传统的传递函数和相干函数分析的基础上结合频率统计,选出优势频率的方法来考察噪声源对车内噪声的影响,为制定客车车内噪声治理方案提供了可靠的依据.

Wholly reducing bus interior noise level needs to consider multi-paths by which several noise sources radiate sound into the bus. If dividing the interior space of a bus into several parts, the same number of noise transfer paths will form relative to one noise source path. Meanwhile, in different working condition, the measuring of the same noise transfer path gives results that have minor offset of peak values positions between each test. So a new method is proposed that combines the traditional transfer function and coherence function analysis with the statistics of frequencies to obtain the dominant frequencies, which can reflect how the noise sources influence the bus interior noise level in frequency domain, and which will provide reliable references to make up plans in reducing the bus interior noise.