轴-艇耦合系统声振仿真中的不规则频率问题  

Irregular frequency problem of vibroacoustic simulation of a shaft-hull system

作　　者：段嘉希 张林[1,2] 孙雪海 殷丽君 笪良龙 DUAN Jia-xi;ZHANG Lin;SUN Xue-hai;YIN Li-jun;DA Liang-long(Department of Navigation Observation Communication,Naval Submarine Academy,Qingdao 266199,China;Qingdao Marine Science and Technology Center,Qingdao 266237,China)

机构地区：[1]海军潜艇学院航海观通系,山东青岛266199 [2]青岛海洋科技中心,山东青岛266237

出　　处：《船舶力学》2024年第10期1611-1621,共11页Journal of Ship Mechanics

基　　金：国家自然科学基金资助项目(52201392);国家重点研发计划项目(2021YFC3100900)。

摘　　要：采用边界元方法求解频域流固耦合问题时,在内域虚拟流场的共振频率处会出现不规则频率问题,在这些不规则频率处辐射声场的求解常常出现较大波动。为研究实尺度潜艇的水下振动声辐射,本文建立基于Suboff艇型的轴系-艇体耦合系统。基于有限元/边界元法,分别采用/不采用消除不规则频率的封闭虚拟阻抗曲面(CVIS)法,计算轴系-艇体耦合系统的中低频段振动及辐射噪声。结果表明:(1)对于湿表面外形较复杂的细长艇体,同样会出现不规则频率,甚至连成“不规则频带”;(2)若不消除不规则频率,不规则频率处的辐射声压级有较大误差,在深海环境中可以“污染”到远场会聚区处;(3)对于主体结构为细长圆柱壳的艇形,首个不规则频率可参照与之尺度相当的细长圆柱壳不规则频率的表达式得出,首个无量纲不规则频率约为ka=2.4。If the fluid-structure interaction problem in frequency domain is solved by boundary element method,irregular frequencies will appear at the resonant frequencies of virtual interior fluid domain and exhibit large fluctuation.In order to investigate the underwater acoustic radiation properties of a full-scale submarine,a shaft-hull coupled system was established based on Suboff model.The FE/BE method was adopted to calculate the vibroacoustic radiation of the system in low-and medium-frequency.The closed virtual impedance surface(CVIS)method was respectively used and not used to study the influence of irregular frequencies.It is shown that:(1)for slender submarine hull with complicated shape,irregular frequencies are not only negligible,but even exhibit in continuous irregular bands;(2)enormous errors will occur if irregular frequencies are not eliminated,and convergence zones in far field of deep ocean environment are also“contaminated”;(3)for submarine whose the main body is constructed as slender cylindrical shell,the 1st irregular frequency can be obtained according to the analytical expression of the irregular frequencies of slender cylindrical shell,and the non-dimensional 1st irregular frequency is about ka=2.4.

关 键 词：边界元 振动声辐射 不规则频率 会聚区 

分 类 号：TB53[理学—物理]