本文根據Hsu等人 (2001) 所發展拋物線型態演進型態緩坡方程式 (EEMSE) 以及Miles (1981) 理論，探討波浪通過複合式系列潛堤的布拉格反射效應，並進行水工模型試驗校核數值模式之計算結果。比較結果顯示，在不同波浪條件和複合式人工沙漣之組合之情況下，理論解析、數值模擬和試驗結果呈現合理之一致性。數值模擬結果顯示，利用複合式人工沙漣可有效增加主頻波、次頻波、分諧波和高諧波布拉格共振區帶寬效果，改善單一頻率之波浪產生一個布拉格共振之限制，增加布拉格共振在各種不同頻率之適用範圍。本文同時探討各參數對波浪通過複合式系列潛堤布拉格反射之影響，這些參數包括潛堤間距差、潛堤個數、相對堤高、潛堤寬度間距比、波浪入射角度以及波浪條件，計算結果顯示，利用不等間距系列潛堤可以提高布拉格反射效果，亦可增加布拉格共振的帶寬，隨潛堤個數、堤高及間距的增加，反射率和帶寬亦隨之增加。

In this paper, the Bragg reflection from multiply composite artificial bars is investigated through Miles’ theory (1981) and a numerical model developed by Hsu et al. (2001). The numerical model is based on an Evolution Equation for the Mild-Slope Equation (EEMSE) in which the higher-order terms neglected in the mild-slope equation are retained to enhance the overall prediction capability for steep ripple beds. Numerical results are fairly compared with theory as well as experiments. It is shown that the performance of the Bragg resonance can be greatly improved by a proper design of multiply composite artificial bars. Affecting factors on Bragg reflection, such as the difference of spacing, the number of bars, the relative bar height, the incident wave angles and the bar spacing were discussed.

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