复杂双层壳体声辐射性能分析

Analysis of sound radiation characteristics of complex double shells

研究了加肋的环板双层壳体的振动和声辐射性能,采用经典Flugge微分算子描述壳体的运动,通过将加强构件等效为反力和反力矩加在内外壳体的表面上而引入壳体振动方程,并利用Helmholtz波动方程和壳体表面的位移连续条件来解位于内层壳和外层壳之间的环形流场,最终建立和求解了双壳体声-流体-结构耦合方程,详细讨论了双壳体参数和双壳间连接型式的变化对其声辐射性能的影响。得出了以下结论:双层壳体内外壳间距减小,内外壳的耦合作用就越强,壳体辐射声功率和表面振动均方速度级升高,外壳的“屏蔽”作用就越不明显;内外壳厚度的改变对壳体振动速度级有较大的作用,对声辐射的影响不是很明显,厚度越大,振动速度级就越低。

The double stiffened shell connected by annular plates is systematically studied. The shell motion is obtained using the classical Flugge operator, the effects of stiffeners are induced into vibration equation by treating them as reverse forces and moments on the shell, and the fluid field between the inner shell and outer shell is solved by applying Helmholtz equation and the continuity conditions of the displacement on the surface of fluid-structure. At last the vibration equation coupled by the sound-fluid-structure are constituted and solved. The effects of the double shell parameters and linked types between the double shells on the sound radiation are discussed in detail. The following conclusions can be obtained: The smaller the space between the inner shell and outer shell is, the stronger the coupling of the inner shell and outer shell is, the higher the radiated power and radial quadratic velocity is, the more indistinct the shield of the outer shell is. The changes of the thickness of the inner shell and outer shell influenced the radial quadratic velocity greatly, and influenced the radiated power indistinctly. The thicker the thickness is, the lower the radial quadratic velocity is.