小水线面双体船螺旋桨激励船体振动研究（英文）

Vibration due to Propeller-Shaft-Hull Coupling of a SWATH

文章研究了小水线面双体船的桨—轴—船体耦合系统在螺旋桨受宽带力激励下的纵向振动特性。建立了考虑周围流体介质作用的桨—轴—船体动态耦合系统的声振数值计算模型,经实船试验表明计算结果与试验结果吻合较好。采用该模型计算分析了桨—轴—船体耦合系统的振动特性。作用在螺旋桨上的激励力传递到船体时,受到轴系子系统的调制作用及推力轴承基座结构的刚度影响,在轴系一阶和二阶纵向振动模态处出现动力放大;考虑螺旋桨的弹性变形时,激励力在螺旋桨的桨叶若干纵向振动模态频率上也出现了明显的放大。在这些低频段的振动模态频率上,船体结构受放大的激励力作用,容易产生共振及声辐射。

Longitudinal vibrational characteristics of a Small Waterplane Area Twin Hull （SWATH） ship due to propeller-shaft-hull structure coupling subject to broadband forces on the propeller are investigated. An integrated vibro-acoustic numerical model comprised of the propellers, shafts and ship structures, as well as the entrained sound fluid is developed. Through experiments, measured data agree well with numerical results. Based on this numerical model, the vibration characteristics of the SWATH due to propeller-shaft-hull structure coupling are analyzed. The numerical results show that propeller-shaft-hull coupling can result in the dynamic magnification effect at the first and second longitudinal resonance frequencies of the shaft. Moreover, when the deformation of propellers is taken into account, the similar dynamic magnification is found at certain resonance frequencies of the blades. Such modes for the shaft, the propeller, and their coupling generally exist in low frequency range, so that the dynamic magnification of propeller forces can easily lead to excessive structural vi-bration and sound radiation.