实船设备结构振动和水声声强测试分析及噪声源的判别

Measurements of Vibration and Underwater Noise Intensity of a Ship and Identification of Main Exciting Sources

通过对船上设备和船体的振动、近远场水噪声声压以及主机舱左舷外水声声强分布的测量和对振动与声的相干分析 ,判断主、辅机激振的耦合对产生声的影响。通过近场声强分布 ,分析结构和声场耦合、能量交换和有效辐射。提出用声强分布计算频带内噪声辐射声功率占总声功率的比例 ,结合主、辅机振动谱综合分析方法 。

The vibration of main electric engines, auxiliary equipments and the hull is measured by accelerator sensors. Sound pressure in near and far fields are measured with hydrophones. By a line sound intensity probe array scanning the field, the underwater sound intensity distribution nearby the left side of the ship is obtained. The detailed characteristics of acoustic energy flow near the hull is shown, and then the coupling effect between the structure and the acoustic field is expressed also. With the intensity distribution, the underwater sound power radiating from the subsurface cabin is calculated. The ratio of the sound power in different frequency bands to total sound power is calculated also. A method is suggested and brought into practice with which the identification of main exciting sources can be carried out, by synthetically analyzing to ratio in different frequency bands and with the vibratory spectra of all the exciting machinery.