舷侧阀通海口结构形式对声学性能的影响

船舶内部包含大量的管路系统,舷侧阀排出口的结构形式直接影响船舶整体减振降噪的效果。选取实船典型管路系统的出口通海口结构为研究对象,建立通海口、管路系统、泵、船体外壳模型,利用数值仿真软件Fluent分析通海口结构的流场稳定性以及外部流场声压。通过研究多种通海口结构优化方案,明确了通海口声学性能较优的低噪声通海口。并分析了管路系统换装低噪声通海口后,整体管路系统中的通海口区域流场水动力噪声性能的变化规律。结果表明:相较实船通海口,低噪声通海口能有效增加通海口内部流场的稳定性,降低外部流场声压,有一定的降噪效果。

The effect of the sea opening structure on the ship side on the structural acoustic characteristics

Typical marine ships contain large amount of piping systems, and the relevant sea opening structures directly influence the acoustic characteristics of the hull.In this paper, the sea opening of typical piping systems is taken as the research subject, and an analyzing model is established in Fluent, which includes pump, piping system, hull and sea opening.Meanwhile, the sound pressure of the flow field and external field is analyzed.By comparing the optimized models for different fluent areas of the sea opening, a low noise structure is confirmed that is capable of improving the structure's acoustic characteristic significantly.Besides, the variation of the hydrodynamic noise of the whole piping system unit that uses low noise sea opening and the original structure is studied.The results indicate that the low noise sea opening of structure optimization plays a key role in noise reduction, which improves the stability of the whole fluent area and reduces the fluid pressure in the far-field.