The present study aims to give general hints about hydrodynamic interactions for water wave diffraction on a super large floating structure composed of a large number of box-shaped modules with many small gaps in betw...The present study aims to give general hints about hydrodynamic interactions for water wave diffraction on a super large floating structure composed of a large number of box-shaped modules with many small gaps in between. And meanwhile, it also aims to seek for an effective way to take the gap influence into consideration without numerical difficulties existing in conventional methods. An asymptotic matching technique is exploited by virtue of the smallness of gaps. Formal potential solutions are established for the near field around the gap ends and the far field away from gap ends, respectively, and the unknowns in those solutions are uniquely determined by asymptotic matching. The eigen-function expansion method is used for the outer far field and a series of pulsating sources at each gap end is introduced to simulate the gap influence. Strong hydrodynamic interaction is observed and a new resonant phenomenon, the mechanism of which differs absolutely from any known ones, is revealed in the present study. Sharp peak responses for both vertical and horizontal wave-exciting forces on each block are found around some special resonance frequencies, which depend on the draft of the structure and the gap width. The present results are of practical significance to the design of links (connectors) of modules for super large floating structures. And the importance is also closely related to the hydro-elasticity analysis for super large floating structures, in which local loads may be as important as the integrated loads.展开更多
In the present investigation, influence of gaps between multiple floating structures on wave forces is examined. Strong and complicate hydrodynamic interactions between the floating bodies are observed and the numeric...In the present investigation, influence of gaps between multiple floating structures on wave forces is examined. Strong and complicate hydrodynamic interactions between the floating bodies are observed and the numerical computations have proved the existence of the sharp peak force response on each floating body at some special resonant wave numbers. The resonant wave number is also proved to be around kL=nπ(n=1, 2, …, ∞) with a corresponding frequency shift. A small yet finite gap width will also give influence on the resonant frequency and resonant amplitude of the wave forces, but when the distance between two aligned box-shaped floating bodies becomes big enough, the hydrodynamic interaction can be neglected. The strong hydrodynamic interaction feature has its own important practical significance for the design of module structures and the links (connection) in the whole floating body system. Moreover, the importance is closely related to the hydro-elasticity analyses of a multiple box-shaped floating body system, in which local loads may be as important as the integrated loads.展开更多
Influence of gaps on hydrodynamic interactions of multiple floating structures is considered in the present investigation. Strong and complicate hydrodynamic interactions between the floating bodies are observed and t...Influence of gaps on hydrodynamic interactions of multiple floating structures is considered in the present investigation. Strong and complicate hydrodynamic interactions between the floating bodies are observed and the numerical computations have showed the existence of the sharp peak force response on each floating body at some special resonant wave numbers, which are also proved to be around kL =nπ （n= 1, 2, ...,∞） with a corresponding frequency shift. Width and depth of a gap also give influences on the resonant frequency and resonant amplitude of added mass and damping forces due to the radiation motions of the multiple bodies. The strong hydrodynamic interaction feature may have a big influence on the integrated loads of multiple floating structures system.展开更多
A 3-D time domain method is developed to investigate the gap influence on the wave threes for 3-D multiple floating structures. Special hydrodynamic resonance due to small gaps between multiple floating structures on ...A 3-D time domain method is developed to investigate the gap influence on the wave threes for 3-D multiple floating structures. Special hydrodynamic resonance due to small gaps between multiple floating structures on wave forces is examined. Strong and complicate hydrodynamic interactions between the floating bodies are observed and the numerical computations have proved the existence of the sharp peak force response on each floating body at some special resonant wave numbers. By comparison with the results from the frequency domain technique, the results obtained from the time domain method reveal the similar resonant phenomena and hydrodynamic interaction. The resonant wave numbers are also proved around kL-nπ （n = 1,2 ……∞） with a corresponding frequency shift. The strong hydrodynamic interaction feature is practically significant for the design of module structures and the links （connection） in whole the floating body system.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.59879011 and 19732004)the Foundation of the Ministry of Education of China
文摘The present study aims to give general hints about hydrodynamic interactions for water wave diffraction on a super large floating structure composed of a large number of box-shaped modules with many small gaps in between. And meanwhile, it also aims to seek for an effective way to take the gap influence into consideration without numerical difficulties existing in conventional methods. An asymptotic matching technique is exploited by virtue of the smallness of gaps. Formal potential solutions are established for the near field around the gap ends and the far field away from gap ends, respectively, and the unknowns in those solutions are uniquely determined by asymptotic matching. The eigen-function expansion method is used for the outer far field and a series of pulsating sources at each gap end is introduced to simulate the gap influence. Strong hydrodynamic interaction is observed and a new resonant phenomenon, the mechanism of which differs absolutely from any known ones, is revealed in the present study. Sharp peak responses for both vertical and horizontal wave-exciting forces on each block are found around some special resonance frequencies, which depend on the draft of the structure and the gap width. The present results are of practical significance to the design of links (connectors) of modules for super large floating structures. And the importance is also closely related to the hydro-elasticity analysis for super large floating structures, in which local loads may be as important as the integrated loads.
文摘In the present investigation, influence of gaps between multiple floating structures on wave forces is examined. Strong and complicate hydrodynamic interactions between the floating bodies are observed and the numerical computations have proved the existence of the sharp peak force response on each floating body at some special resonant wave numbers. The resonant wave number is also proved to be around kL=nπ(n=1, 2, …, ∞) with a corresponding frequency shift. A small yet finite gap width will also give influence on the resonant frequency and resonant amplitude of the wave forces, but when the distance between two aligned box-shaped floating bodies becomes big enough, the hydrodynamic interaction can be neglected. The strong hydrodynamic interaction feature has its own important practical significance for the design of module structures and the links (connection) in the whole floating body system. Moreover, the importance is closely related to the hydro-elasticity analyses of a multiple box-shaped floating body system, in which local loads may be as important as the integrated loads.
文摘Influence of gaps on hydrodynamic interactions of multiple floating structures is considered in the present investigation. Strong and complicate hydrodynamic interactions between the floating bodies are observed and the numerical computations have showed the existence of the sharp peak force response on each floating body at some special resonant wave numbers, which are also proved to be around kL =nπ （n= 1, 2, ...,∞） with a corresponding frequency shift. Width and depth of a gap also give influences on the resonant frequency and resonant amplitude of added mass and damping forces due to the radiation motions of the multiple bodies. The strong hydrodynamic interaction feature may have a big influence on the integrated loads of multiple floating structures system.
基金the National Natural Science Foundation of China (Grant No. 50639020)the National High Technology Research and Development Program of China (863 Program, Grant No. 2006AA09Z332).
文摘A 3-D time domain method is developed to investigate the gap influence on the wave threes for 3-D multiple floating structures. Special hydrodynamic resonance due to small gaps between multiple floating structures on wave forces is examined. Strong and complicate hydrodynamic interactions between the floating bodies are observed and the numerical computations have proved the existence of the sharp peak force response on each floating body at some special resonant wave numbers. By comparison with the results from the frequency domain technique, the results obtained from the time domain method reveal the similar resonant phenomena and hydrodynamic interaction. The resonant wave numbers are also proved around kL-nπ （n = 1,2 ……∞） with a corresponding frequency shift. The strong hydrodynamic interaction feature is practically significant for the design of module structures and the links （connection） in whole the floating body system.
