波浪通過單一浪形潛堤反射率之研究

Reflection Coefficient of Water Waves by a wavy-type Submerged Breakwater

岳景雲(Ching-Yun Yueh) ； 曹登皓(Deng-How Tsaur) ； 邱永芳(Yon-Fang Chiu)

《海洋工程學刊》 4卷1期 (2004/10) Pp. 23-43

https://doi.org/10.6266/JCOE.2004.0401.02

摘要

本文利用波浪通過不透水矩形潛堤上方後會產生波長變短和消波減壓的特性，以及波浪通過海底底床沙漣(sand ripples)所產生的布拉格反射「Bragg reflection」，互相組合成堤頂有如波浪狀的浪形(wavy-type)潛堤來探討波浪反射率。數值計算方法是採用邊界元素法(BEM)，解析規則波正向或斜向入射通過水中浪形潛堤後其反射率之大小。並利用斷面水槽進行水工模型試驗，在波浪正向入射時，改變浪形潛堤個數、堤高及無因次週波數，經由試驗結果顯示反射率值與數值方法所得到結果變化趨勢相當一致，利用本文數值模式可以得到精度不錯的結果。

關鍵字

浪形潛堤 ； 沙漣 ； 布拉格共振

並列摘要

In this study, the phenomena of submerged breakwater may deduct the passing wave lengths and energies, and sand ripple may cause the Bragg reflection were combined to form a submerged wavy-type breakwater. Numerical simulations with boundary element method and hydraulic model tests in a wave flume were employed to investigate its effectiveness by examining the reflection and transmission coefficients in different incident wave conditions. The results show that calculated reflection coefficient was found to agree with that found in experiments on non-breaking waves.

並列關鍵字

wavy-type submerged breakwater ； sand ripples ； Bragg resonance