﻿ 单/双层水下结构振动声辐射研究
 舰船科学技术  2017, Vol. 39 Issue (1): 17-20 PDF

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

Research on the vibration and acoustic radiation of single and double layers underwater structure
HE Qi-wei1,2, LI Hai-feng3, YU Xiang1,2
1. Office of Research and Design, Naval University of Engineering, Wuhan 430033, China;
2. National Key Laboratory on Ship Vibration and Noise, Wuhan 430033, China;
3. College of Power Engineering, Naval University of Engineering, Wuhan 430033, China
Abstract: To research the vibration and acoustic radiation characteristics of the single-layer and double-layer underwater structure which are the typical structures of the submarine, the single-layer and double-layer propeller-shaft-hull coupled structures are established, the three-dimensional sono-elastical theory and acoustic analysis software are applied to analyze the sound source level curve of the coupled structure under three different exciting such as propeller exciting, external fluid exciting and internal mechanical exciting. The analysis results show that the total radiated acoustic power of single-layer underwater structure is less than double-layer under propeller exciting, but higher than double-layer under external fluid exciting and internal mechanical exciting.
Key words: Single and double layers structure     propeller-shaft-hull     vibration     acoustic radiation     sound source level
0 引言

1 三维声弹性力学理论

 ${u} = \sum\limits_{r = 1}^m {{{u}_r}{q_r}} = \sum\limits_{r = 1}^m {\left\{ {{u_r},{v_r},{w_r}} \right\}{q_r}},$ (1)

 $\Phi \left( {x,y,z,t} \right) = \sum\limits_{r = 1}^m {{\phi _r}\left( {x,y,z,t} \right)} ,$ (2)

 ${\nabla ^2}\phi- \frac{{{\partial ^2}\phi }}{{\partial {t^2}}} = 0,$ (3)

 $\frac{{\partial {\phi _r}}}{{\partial {{n}}}} = iw\left( {{u_r}{n_1} + {v_r}{n_2} + {w_r}{n_3}} \right)。$ (4)

 $G\left( {P,Q} \right) = \frac{1}{{4\pi {r_1}}}{e^{- ik{r_1}}}- \frac{1}{{4\pi {r_2}}}{e^{- ik{r_2}}}。$ (5)

 $\phi \left( P \right) = \frac{1}{{4\pi }}\int \!\!{\int_{\bar S} {\sigma \left( Q \right)G\left( {P,Q} \right){\rm{d}}{S_Q}} } ,$ (6)

 $\left[ {a + A} \right]\left\{ {\ddot q} \right\} + \left[ {b + B} \right]\left\{ {\dot q} \right\} + \left[ {c + C} \right]\left\{ q \right\} = \left\{ \Xi \right\}$ (7)

 $\left. {\begin{array}{*{20}{l}} {{A_{rk}}}\\ {{B_{rk}}} \end{array}} \right\} = \left. {\begin{array}{*{20}{l}} {\frac{1}{{{\omega ^2}}}{\rm{Re}}}\\ {- \frac{1}{\omega }{\rm{Im}}} \end{array}} \right\}\left[ {\rho \int \!\!{\int_{\bar S} {{ n} \cdot { u_r}\left( {i\omega } \right){\phi _k}{\rm{d}}S} } } \right],$ (8)
 ${C_{rk}} =- \rho \int_{\bar S} { n \cdot { u_r} \cdot g \cdot {\omega _k}{\rm{d}}S} ,$ (9)

 $\begin{array}{l} p\left( {x,y,z,t} \right) =- \rho \sum\limits_{r = 1}^m {\frac{{\partial {\phi _r}}}{{\partial t}}} =- \rho \sum\limits_{r = 1}^m {\left( {i\omega } \right)} \times \\ \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\left( {\frac{1}{{4\pi }}{{\left( {\int {\int_{\bar S} {\sigma \left( Q \right)G\left( {P,Q} \right)dS} } } \right)}_r}} \right)。\end{array}$ (10)
2 桨-轴-壳体计算模型

 图 1 计算模型 Fig. 1 Calculation model
3 数值计算及结果分析

 ${L_s} = 10\lg \frac{{P/\left( {4\pi } \right)}}{{{P_0}}}。$ (11)

 图 2 螺旋桨横向激励下单/双层结构声源级曲线 Fig. 2 Sound source level curve of single and double layers structures under propeller vertical exciting

 图 3 螺旋桨纵向激励下单/双层结构声源级曲线 Fig. 3 Sound source level curve of single and double layers structures under propeller longitudinal exciting

 图 4 外部水噪声激励下单/双层结构声源级曲线 Fig. 4 Sound source level curve of single and double layers structures under external fluid exciting

 图 5 内部机械激励下单/双层结构声源级曲线 Fig. 5 Sound source level curve of single and double layers structures under internal mechanical exciting
4 结语

1）在螺旋桨横向力和纵向力作用下，单/双层水下结构声源级曲线相互交叉，声辐射相差不大，在 10～150 Hz 频段内单层水下结构声辐射总声级略低于双层结构。

2）在外部流体激励力和内部机械设备激励力作用下，单层结构声辐射声源级曲线高于双层结构，因此，在 10～150 Hz 频段内单层水下结构声辐射总声级明显高于双层结构。

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