On wave diffraction of two-dimensional moonpools in a two-layer fluid with finite depth

OCEAN ENGINEERING

卷:173

Article

Xu, Xin^1,2  Song, Xingyu^1,2  Zhang, Xinshu^1,2  Yuan, Zhiming^3,4 

[1] Shanghai Jiao Tong Univ, State Key Lab Ocean Engn, Shanghai 200240, Peoples R China

[2] Collaborat Innovat Ctr Adv Ship & Deep Sea Explor, Shanghai 200240, Peoples R China

[3] Univ Strathclyde, Dept Naval Architecture Ocean & Marine Engn, 100 Montrose St, Glasgow G4 0LZ, Lanark, Scotland

[4] Jiangsu Univ Sci & Technol, Sch Naval Architecture & Ocean Engn, Zhenjiang 212003, Jiangsu, Peoples R China

关键词: Moonpool;    Two-layer fluid;    Wave diffraction;    Resonance;    Piston mode;    Sloshing mode;   

DOI  :  10.1016/j.oceaneng.2018.12.037

来源: Elsevier

【 摘 要 】

This paper studies the wave diffraction problem of two-dimensional moonpools in a two-layer fluid by using domain decomposition scheme and the method of eigenfunction expansion. Wave exciting forces, free surface and internal wave elevations are computed and analyzed for both surface wave and internal wave modes. The present model is validated by comparing a limiting case with a single-layer fluid case. Both piston mode and sloshing mode resonances have been identified and analyzed. It is observed that, compared with the solutions in surface wave mode, the wave exciting forces in internal wave mode are much smaller, and show more peaks and valleys in low-frequency region. As the wave frequency increases, the bandwidth of sloshing mode resonances decreases. Extensive parametric studies have been performed to examine the effects of moonpool geometry and density stratification on the resonant wave motion and exciting forces. It is found that, for twin bodies with deep draft in surface wave mode, the decreasing density ratio has little effects on the sloshing mode resonance frequencies but can somehow suppress the horizontal wave exciting forces and surface wave elevations around piston mode resonance region. In addition, the presence of lower-layer fluid can lead to the reduction of piston mode resonance frequency.

【 授权许可】

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