The Absorption of Wave Energy by Floating Structures
|關鍵字:||浮式結構物;波能;效率;floating structures;wave energy;efficiency|
Based on a two dimensional linear water wave theory, the boundary element method is developed and applied to study the effectiveness of a wave energy absorber in water to finite depth. The present study is concerned with wave energy which is defined as the incident wave power per unit crest length, efficiency of an absorber defined as the ratio of the wave energy absorbed by the floating structures per wave period to the available energy of the incident wave, and the best efficiency defined as wave energy absorbed by structures and the available energy of the incident wave are the same. In this thesis, the structures have three forms: a right wedge, a symmetric wedge, and a vertical flat plat; we assume that front two structures are constrained to oscillate in heave, and the third structures is constrained to oscillate in sway. The accuracy of the present numerical model is proved by comparing results of present numerical model, and laboratory experiment. When the boundary in back of the structures is radiation condition, the absorption of wave energy complete hardly by absorber, but exchange radiation boundary for vertical sidewall, the best efficiency was made in some relative depths. By changing the shape of the structures or the distance from structures to sidewall, the best efficiency relative to relative depths are different; in other words, the best efficiency of known wave conditions was got by changing the shape or location of the structures. Using the vertical flat plat to absorb wave energy, the arrange of the best efficiency relative to relative depths is wider than other two; considering above 90 percent of efficiency, using the vertical flat plat to absorb wave energy, the arrange of relative depths is also wider than other two. In summary, about three absorbers of the present study, the available of energy absorbed by vertical flat plat is better than others.
|Appears in Collections:||Thesis|