Experiments of opening and cavity shear flow-induced vibration and structural coupling resonance

XIONG Jishi1,LV Shijin2,QIU Changlin1,WANG Chunxu1,CHEN Zhigang1

Chinese Journal of Ship Research - - 刘西安等:某科考船艉部舱段振动固有频率计算方法 -

1 China Ship Development and Design Center,Wuhan 430064,China 2 China Ship Scientific Research Center,Wuxi 214082,China Abstract: In order to discuss opening and cavity shear flow-induced vibration and structural coupling resonance, experiments of opening and cavity shear flow-induced vibration and structural noise control are carried out. The impact of the opening size, flow velocity and cavity thickness on shear oscillation noise, self-noise in the cavity and radiated noise are analyzed. The results show that the empirical formula of the opening shear oscillation in air is also applicable to the condition underwater, which the shear oscillation and amplitude of modal frequencies are directly proportional to the flow velocity; in case that no coupling resonance occurs, the thickness of the cavity wall will bring slight influence on the amplitude of the shear oscillation, but not on the mode frequencies; also the coupling of shear oscillatory mode and cavity wall mode show dramatic coupling resonance under certain conditions, and leads to self-noise and acoustic radiation. The findings supply useful exploration and technical support concerning the application of opening and cavity structural noise control measures. Key words:shear oscillation;elastic walls;coupling resonance

0引言

潜艇由于潜浮的需要,在艇身开设了数量众多、样式各异的流水孔和压载水舱开口,以及其他 各种大小的开口,破坏了艇体表面的光顺性与连续性,致使流动发生分离。在沿流向跨越开孔的内、外流之间,存在着不稳定的剪切层波动,一方面会直接辐射噪声,另一方面会在流水孔后缘局

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