單點錨錠圓柱浮體的消波機制研究

Abstract

本文研究主要目的在於估算單點錨碇圓柱浮體在不同的波浪條件下，探討單索錨碇圓柱浮體消耗波浪能量的百分比。 以梁（2000）所設計的半封閉圓管來做為實驗的水工模型，理論計算方面以Morison公式作為力分析的基礎，先計算出單根圓柱浮體在無波浪場下，將浮體拉離原位一個角度後再放開後，第一個半週期的平均消耗功率。再透過乘上一個修正值的間接計算方式，使得無波浪場下的平均消耗功率可以在波浪場中使用。 透過水工模型實驗，於一固定區域內設置數量不等的浮體模型，以隨機的方式排列，以正向規則入射波為波浪條件，量測波浪通過圓柱浮體設置區域前後的波高，獲得波浪能量損失，進而得到波浪能量消耗百分比。實驗得到入射波形尖銳度增加及相對水深減小時，透射率減小，消波效能較好。實驗結果與理論解析解作比較，驗證理論公式的正確性與誤差。 最後透過理論公式，來預測在不同的波浪條件下，欲達到某程度的消波效果，需設置多少圓柱浮體。

The purpose of this paper is to estimate the wave sheltering of singly-moored spar buoy under different wave conditions, it is discussed that the singly-moored spar buoy consumes the percentage of wave energy. The spar buoy was constructed by a semi-closed pipe, which was designed by Liang(2000). The theory regards Morison formula as the foundation analyzed. First, unlock after moving the spar buoy in an angle under the quiet surface of water, calculate the power of average consumption of half-period. And then calculate the way through the indirectness of taking advantage of having a revising value, let this power of average consumption can be used in the wave field. Making use of the experiment of models, set up the model of the quantity in the regular area, arranges in way at random, regard regular wave as the wave condition, measure the height of wave before and after the area, and then received wave energy consumption percentage. The transmission coefficient also decreases as the wave steepness increases and the relative depth decreases. The experimental result is compared with theory, verify the exactness and error of theory formulae. Finally, predict under different wave conditions through the theory formula, how many singly-moored spar buoy are set up, how much result.