﻿ 弹性板-圆柱壳水下声辐射特性及影响因素
 舰船科学技术  2016, Vol. 38 Issue (11): 44-47 PDF

1. 海军工程大学 动力工程学院, 湖北 武汉 430033 ;
2. 船舶振动噪声重点实验室, 湖北 武汉 430033

Underwater acoustic radiation characteristics and influencing factors of elastic plate-cylindrical shell
ZHANG Yang-yang1,2, LOU Jing-jun1,2, ZHU Shi-jian1,2
1. Naval University of Engineering, Institute of Power Engineering, Wuhan 430033, China ;
2. National Key Laboratory on Ship Vibration and Noise, Wuhan 430033, China
Abstract: Elastic plate-cylindrical shell is one of the commonly used structures in the field of engineering, and its vibration and acoustic radiation characteristics are the focus of the current attention. Based on Abaqus software, the model of elastic plate-cylindrical shell structure is established. The vibration and underwater sound field distribution are calculated by using three dimensional theory of sound elasticity, and the way to reduce acoustic radiation is studied. Results show that, underwater acoustic field of the elastic plate-cylindrical shell has obvious symmetry, and the sound pressure level is significantly affected by the vibration of the elastic plate. By increasing the thickness of the elastic plate, the L-shaped cross section of the reinforced rib and one horizontal plane of the cylindrical shell can effectively reduce the underwater acoustic radiation of cylindrical shell.
Key words: elastic plate     cylindrical shell     reinforced rib     acoustic radiation
0 引言

1 模型简介

 图 1 弹性板-圆柱壳模型 Fig. 1 Elastic plate-cylindrical shell model

2 水下声辐射特性 2.1 三维声弹性理论计算水下声辐射

 $\left\{ U\left( t \right) \right\}=\left[ D \right]\left\{ q\left( t \right) \right\}=\sum\limits_{r=1}^{m}{\left\{ {{D}_{r}} \right\}{{q}_{r}}\left( t \right)}\text{,}$ (1)

 ${\boldsymbol a} \!\left\{ \ddot{q}\left( t \right) \right\}\!\!+\!\! {\boldsymbol b} \left\{ \dot{q}\left( t \right) \right\}\!\!+\!\! {\boldsymbol c} \left\{ q\left( t \right) \right\}\!=\!\left\{ {{f}_{e}}\left( t \right) \right\}\!+\!\left\{ {{f}_{p}}\left( t \right) \right\}\text{。}$ (2)

 \begin{aligned} & \left[ { - {\omega ^2}\left( {\left[ a \right] \!+\! \left[ {\boldsymbol A} \right]} \right){\rm{ \!+\! i}}\omega \left( {\left[ b \right] \!+\! \left[ {\boldsymbol B} \right]} \right) \!+\! \left( {\left[ c \right] \!+\! \left[ {\boldsymbol C} \right]} \right)} \right]\text{，}\\ & \quad \quad \,\,\left\{ q \right\} = \left\{ {{f_e}\left( \omega \right)} \right\} + \left\{ {T\left( \omega \right)} \right\}\text{。} \end{aligned} (3)

 $\left\{ U \right\}\text{=}\sum\limits_{\text{r}=1}^{m}{\left\{ {{D}_{r}} \right\}}{{q}_{r}}\text{。}$ (4)

 ${{\phi }_{R}}\left( x,y,z \right)=\sum\limits_{r=1}^{m}{{{\phi }_{r}}\left( x,y,z \right)}{{q}_{r}}\text{。}$ (5)

 \begin{aligned} & p\left( x,y,z \right)=-{{\rho }_{0}}\left( i\omega +\overrightarrow{W}\cdot \nabla \right){{\phi }_{R}}= \\ & \quad \quad \quad \quad \quad \!\!-{{\rho }_{0}}\left( i\omega +\overrightarrow{W}\cdot \nabla \right)\sum\limits_{r=1}^{m}{{{\phi }_{r}}\left( x,y,z \right){{q}_{r}}}\text{。}\end{aligned} (6)

2.2 水下辐射声场特性及分布规律

 图 2 测点分布 Fig. 2 Testpoints distribution

 图 3 测点处的辐射声压级 Fig. 3 Sound pressure level of testpoints

 图 4 水下辐射声场云图 Fig. 4 Acoustic radiation field nephogram of underwater
3 影响因素分析

3.1 弹性板厚度的影响

 图 5 弹性板厚度的影响 Fig. 5 Influence of elastic plate thickness
3.2 加强筋截面类型的影响

 图 6 加强筋类型的影响 Fig. 6 Influence of reinforced rib type
3.3 弹性板布置方式的影响

 图 7 弹性板位置的影响 Fig. 7 Influence of elastic plate location
4 结语

1）弹性板的振动模态对圆柱壳水下声辐射有重要影响。在一定频率范围内，弹性板振动引起的圆柱壳声辐射出现较大峰值，必须予以重点关注。

2）弹性板-圆柱壳水下辐射声场呈现明显的对称性，在圆柱壳两端及上下两侧辐射声能量比较集中。

3）弹性板厚度对圆柱壳振动和声辐射有一定影响，在结构允许条件下，采用厚度较大的弹性板可以在一定程度上降低圆柱壳水下声辐射。

4）弹性板加强筋截面类型对圆柱壳振动和声辐射的影响显著，采用L形截面的加强筋可以最大程度降低圆柱壳水下声辐射。

5）在圆柱壳体内水平中面位置布置单个弹性板比对称位置布置双弹性板更能有效降低圆柱壳的振动和水下声辐射。

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