An Experimental Investigation on Reduction Effect of Damping Devices for the Recessing Type Moonpool with a Large Aspect Ratio
An Experimental Investigation on Reduction Effect of Damping Devices for the Recessing Type Moonpool with a Large Aspect Ratio
复制标题
大深宽比凹进式月池阻尼装置减振效果实验研究
DOI：
10.5957/josr.08190045
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发表时间：
2020-08
影响因子：
1.4
通讯作者：
Jiang Zhiyong
中科院分区：
文献类型：
--
作者：
Huang Xianghong;Xiao Wei;Yao Xiongliang;Gu Jiayang;Jiang Zhiyong
与方形和圆形月池相比，长宽比大的矩形月池更有利于设备的安装。为了减少具有大纵横比的矩形月池中的流体运动，在月池中安装了凹槽。然而，对于大纵横比凹陷型月池流体运动的研究却很少。本文通过一系列实验研究了大纵横比凹坑型月池中流体的水动力特性。为了便于对流体运动进行监测，实验采用透明亚克力制成的透明波槽模型。实验结果表明，月池中存在着复杂的流体运动。在共振条件下，流体在月池中剧烈运动。为了减小凹坑式月池中的流体运动，提出了三种阻尼装置：挡板正栅格、挡板负栅格和挡板栅格。实验研究了三种阻尼装置的减振效果。阻尼装置在大多数情况下具有良好的减震效果。入射波周期越小，减振效果越好。
Compared with the square and circle moonpools, the rectangular moonpool with a large aspect ratio is more conducive to install the equipment. To reduce fluid motion in the rectangular moonpool with a large aspect ratio, a recess is installed in the moonpool. However, the fluid motion in a recessing type moonpool with a large aspect ratio has been rarely studied. In this study, a series of experiments are carried out to investigate on the hydrodynamic characteristics of fluid in the recessing type moonpool with a large aspect ratio. To facilitate the monitoring of the fluid motions, experiments are carried out in a transparent wave channel with the model made up of transparent acrylic. According to the experiment results, there are some complicated fluid motions in the moonpool. Under the resonance condition, the fluid moves violently in the moonpool. To reduce the fluid motion in the recessing type moonpool, three damping devices including the positive grid of flaps, the negative grid of flaps, and the grid of baffles are proposed. The reduction effect of the three damping devices is investigated experimentally. The damping devices have good reduction effects at most time. The smaller the incident wave period, the better is the reduction effect.
1. Introduction
The moonpools run vertically through the hull of ships or marine structures, providing a sheltered working environment under harsh ocean conditions. The fluid motion in the moonpool is similar to that in the slit between the ships or rectangular bodies (Faltinsen et al. 2007; Mavrakos & Chatjigeorgiou 2009; Ikeda et al. 2012; Chen et al. 2014; Heo et al. 2014; Zhang & Bandyk 2014; Faltinsen & Timokha 2015; Yu et al. 2017; Gao et al. 2019d). Two dominant types of fluid motions, the piston motion and the sloshing motion, are discussed (Fukuda 1977; Molin 2001; McIver 2005; Kristiansen & Faltinsen 2012; Zhou & Zhang 2013).