加肋圆柱体水下低频辐射声特性研究

为掌握不同激励下加肋圆柱体水下低频辐射声频谱特征,揭示辐射声峰值对应的优势模态及弯纵耦合现象规律,该文利用三维水弹性声辐射计算方法,针对加肋圆柱体的梁模型和有限元壳模型,计算分析其水下不同激励的声源级传递函数,分析声源级曲线峰值与单个模态声源级分量的对应关系,得出垂向激励时,辐射声峰值对应于垂向弯曲模态;轴向激励时,辐射声峰值对应于轴向模态,同时运用壳模型计算结果发现梁模型所不能反映的弯纵耦合现象。比较了不同激励辐射声源级传递函数,得出所分析频带内,轴向单位力激励总声级比垂向略大。并比较不同模型的结果,指出梁模型的适用范围。

Research on acoustic radiation of stiffened cylinder in low-frequency

To obtain the character of acoustic radiation of stiffened cylinder in low-frequency, and disclose the dominant modes corresponding to the peaks of acoustic radiation and the phenomenon of the coupled mode of bending and longitudinal deformation, three-dimensional sono-elastical method is applied to solve the transfer function of acoustic radiation of the beam model and shell model of stiffened cylinder under different exciting. The vertical bending modes corresponding to the peaks under vertical exciting and the longitudinal modes corresponding to the peaks under longitudinal exciting are obtained by using the rela-tion between the source level curve and the component of a single mode. The coupled mode of both bend-ing and longitudinal deformation of the shell model is also obtained, which could not be found of the beam model. By comparing the transfer function of source level under different exciting, the total acoustic power under longitudinal exciting is slightly higher than that under vertical exciting is obtained. The applicability of beam model is identified by comparing the results of shell model and beam model.