液体射流泵空化噪声与振动试验

Experiment on cavitation noise and vibration in liquid jet pump

针对液体射流泵的空化噪声与振动进行了试验研究;运用B＆K加速度仪和水听器对射流泵各部位在不同工况下的空化噪声与振动进行了测量。结果表明：（1）射流泵空化噪声以单极子声源为主,随着流速和紊流度的增大,偶极子作用逐渐增大;（2）射流泵空化噪声与振动随空化程度加剧而更强烈,最强烈处也从喉管向扩散管转移;（3）射流泵面积比越小,达到临界空化前噪声频谱波动越强,临界空化之后噪声谱级趋于平稳,随频率增加而递减;（4）初生空化出现前后噪声在整个频域范围内都有一个较大的跃升,约5-10 dB,此跃升可作为判断初生空化的参考方法;（5）泵体3个正交方向振动并不相同,径向振动较轴向更为明显。

The experimental study on the noise and vibration in liquid jet pump was conducted. The B＆K accelerometer and hydrophone were used for the measurement of the cavitation noise and vibration at different part of jet pump under different operating modes. The measured results reveal that： （ 1 ） The primary source of cavitation noise in jet pump is monopole source and the effect of dipole source increases with the augment of velocity and intensity of turbulence ; （2） With the development of cavitation, the intensity of noise and vibration increase and the most intensive place moves from throat tube to diffuser; （3） Before critical cavitation, the smaller the area ratio is, the stronger the fluctuation of noise spectrum is. In post critical cavitation stage, the noise spectrum degree decreases smoothly with the increase of frequency; （4） When incipient cavitation occurs, there is a sharp increase about 5 - 10 dB at the whole spectrum. This sharp increase can be adopted as an indicator of whether or not the incipient cavitation occurs ; （5） The vibrations in three orthogonal directions are in different modes. The vibration perpendicular to the axial direction overwhelms that to the axial direction.