A vibro-acoustic model of a structurally excited cylindrical shell of infinite length submerged in a heavy fluid at a finite distance from a free surface is presented. Expressions for the shell displacement, the acoustic pressure in the interior cavity of the shell and the acoustic pressure at all field locations in the exterior domain are analytically derived. The formulation for the exterior acoustic pressure is developed using the image method and Graf's addition theorem. Results for the structural and acoustic responses of the cylindrical shell submerged at a finite distance from the free surface and in an unbounded fluid domain are compared. The effects of the shell circumferential modes, interior cavity resonances and proximity of the free surface on the shell acoustic responses are examined. New mechanisms influencing the low frequency vibro-acoustic response of a submerged hull near a fluid boundary are described.

提出了一个无限长的结构激发圆柱壳的振动声学模型，它浸没在距自由表面有限距离的重流体中。壳位移、壳内腔中的声压和外域中所有场位置的声压的表达式是通过解析导出的。外部声压的公式是使用图像方法和格拉夫加法定理开发的。对浸没在离自由表面有限距离处和在无界流体域中的圆柱壳的结构和声学响应的结果进行了比较。检查了壳圆周模式、内腔共振和自由表面接近度对壳声学响应的影响。