侧推器脉动压力及噪声的试验研究

An Experimental Study on Pressure Fluctuation and Noise Induced by Tunnel Thruster

侧推器桨叶负荷重、叶梢间隙很小,比普通螺旋桨更容易产生空泡,因此振动和噪声问题更加突出。公开文献中相关试验研究极少。作者在上海交通大学空泡水筒开展了侧推器脉动压力和噪声的模型试验研究,对于齿轮箱位于桨叶上游的情况,考察了来流速度、螺旋桨转速以及空泡对脉动压力和噪声的影响。试验分析表明前两个因素影响很小;有空泡时的脉动压力和噪声均比无空泡时明显增大;有空泡时,随着空泡数的降低,桨盘面处的压力脉动会进一步加剧,而噪声却下降了。

Cavitation occurs more easily on tunnel thruster blades than on an open propeller due to the small tip clearance and heavy loads, which make serious structural vibration and noise radiation. In this paper, model experiments have been conducted for a tunnel thruster model in the cavitation tunnel in Shanghai Jiao Tong University. Influences of flow speed, impeller＇s rotation speed and cavitation number on fluctuating pressures on the tunnel wall and radiated noise are investigated. Experimental results indicate that influence of flow and impeller＇s rotation speed on the coefficient of fluctuation pressure is negligible. Both The amplitude of pressure fluctuation and sound pressure level are higher in the cavitating condition than in the non-cavitating one. The pressure fluctuation on the impeller disk becomes strong as the cavitation number decreases, whereas the noise does not.