基于等效单摆模型的全开口月池内流体晃动特性研究

摘要

The characters of sloshing fluid in the fully open moonpool can be studied based on the equivalent pendulum mod-el.The equivalent pendulum model and its parameters of the fluid in the fully open moonpool can be derived, as well as the conditions of fluid sloshing. The parameters of equivalent pendulum model can be calculated with deepwater drilling ships as an example, which indicates that the natural vibration parameters of sloshing fluid in fully open moonpool can be got better in a large draught and the main mass of fluid is allocated by the equivalent rigid body. Howerver, the fluid along with the motions of the free surface mainly concentrate on the first-order pendulum. Work in this paper is the base on the further study of the complex coupled motions between different modes of the fluid in floating body-moonpool.%基于等效单摆模型研究底部全开口月池内流体的晃动特性。推导了月池内流体的等效单摆模型及模型参数，分析了用该模型描述全开口月池内流体晃动的条件，以深水钻井船为例计算了其月池内流体晃动的等效单摆模型参数。结果表明：较大吃水时，等效单摆模型可较好的获得全开口月池内流体晃动的自振参数；等效刚体分配了月池内大部分流体的质量，随自由液面运动的流体质量主要集中在一阶单摆。本文工作为进一步研究浮体-月池内流体不同模态间的复杂耦合运动奠定了基础。