摘要
研究潜艇结构振动、声辐射特性随尾后轴承刚度改变的变化规律,对潜艇减振降噪具有十分重要的意义。从振源振动传递路径的声学设计的角度出发,以改变靠近螺旋桨的尾后轴承的刚度为具体措施,采用结构有限元法、结构有限元耦合流体边界元方法,以辐射声功率、湿表面均方法向速度作为衡量结构噪声辐射能力的主要衡量指标,系统地研究潜艇结构振动、辐射噪声谱峰频率和峰值的变化规律。从计算结果可以看出:在低频段,随着尾后轴承刚度的增大,谱峰频率明显向高频移动,第一峰值呈先减小后增大趋势,第二峰值呈明显增大趋势;尾后轴承刚度越小,除第一个谱峰频率附近的窄频带外,在整个计算频段范围内,振动和辐射噪声明显减小。因此,改变尾后轴承刚度,可以使谱峰频率向高频或低频移动,这样就能够使设备激振力的谱峰频率与结构振动及辐射噪声的谱峰频率错开,实现对辐射噪声的控制;降低尾后轴承刚度,在一定频段范围内,能够明显降低潜艇振动和辐射噪声。
The relation between the vibro-acoustic radiation of the submarine hull and the rear bearing stiffness is very important for reducing vibration and noise of the submarine. From the angle of controlling transfer path of exciting force, with the adoption of modifying the stiffness of the rear bearing near the propeller, the structural finite element method and the structural finite element coupled fluid boundary element method are adopted for the numerical calculation, and the acoustic radiation power, mean square normal velocities of the wet surface are adopted as the main indexes to estimate the acoustic radiation ability from the subroutine structures and the characteristics of the vibration and acoustic radiation from the whole structure are studied systemically. From the result, in the lower frequency band, the peak frequencies shift to higher frequency with the increasing of the rear bearing stiffness, and the first peak value increases at first then decreases, but the second peak value decreases obviously; if the rear bearing stiffness is smaller,in the whole frequency band, except the narrowband near the first peak frequency, the level of vibration and noise decreases obviously. By modifying the rear bearing stiffness, the peak frequencies shift to higher frequency or lower frequency, and so that the spectral peak frequencies of the exciting force of the machines and the spectral peak frequencies of the vibration and noise are separated, and as a result, the noise and vibration are controlled. By decreasing the rear bearing stiffness, in some frequency band, the vibration and noise of the submarine are reduced.
出处
《船舶力学》
EI
CSCD
北大核心
2018年第2期235-247,共13页
Journal of Ship Mechanics
基金
国家自然科学基金项目(51479205)
*****演示验证项目(*2011001/101)
关键词
尾后轴承刚度
振动和辐射噪声
谱峰频率
振动传递路径
rear bearing stiffness
vibration and acoustic radiation
spectral peak frequency
transfer path of vibration
