臺灣博碩士論文加值系統

近岸區沖刷帶為陸海環境交互重疊、相互影響之區域，故該區域之波浪動態對於海岸結構物、懸浮物、漂砂與濃度擴散等均有密切關係，往昔許多學者針對輸沙模式進行研究與修正，了解底床剪應力主導輸沙運動，故直接量測底床剪應力之數據，除可了解此區域的波浪運動之動力特性外，亦可提供數值模式修正與工程上之應用。
本研究於成大水工試驗所之造波水槽進行，使用自製剪力板安裝於斜坡上，直接量測底床剪應力。測試之波浪條件為不同波高水深比之孤立波，分別於不同水深條件下進行實驗，同時為了解沖刷帶相對位置之最大剪應力分布，斜坡上之剪力板可移動置斜坡上數個位置，量測不同位置底床剪應力之變化與差異。
實驗之呈現除沖刷帶底床剪應力之時序列變化外，並探討於不同波高水深比與相對位置時，最大底床剪應力之情形。由於沖刷帶溯升時，碎波後之紊流造成底床較為複雜的剪應力變化，而回溯流由於只受重力影響，變化較為規律且穩定。至於摩擦係數 則散亂於一個區間內，然其最大值有利於工程上之安全設計考量，與邊界層外流速推算底床剪應力之依據。

The hydrodynamics in swash zone has been an important subject for scientist and engineers due to its importance and complexity. Direct measurements of bed shear in the swash zone are presented. The data were obtained using a shear plate in laboratory swash zone. Data were obtained across the swash zone. The flow velocities through the full swash cycle were obtained through measured velocity data. The measured stresses and measured flow velocities were subsequently used to back-calculate instantaneous local skin friction coefficients using the quadratic drag law.
The experiments were conducted in a wave flume in Tainan Hydraulics Laboratory. The measurements indicate strong temporal and spatial variation in bed shear stress throughout the swash cycle, and a clear distinction between the uprush and backwash phase. For a single swash event, the maximum uprush bed shear stresses occur in the lower swash zone, within the range 0.05〈x/H 〈0.08.

摘要 1
圖目錄 7
符號說明 10
第1章 緒論 12
1-1研究目的 12
1-2文獻回顧 12
1-3本文組織 14
第2章 實驗設備與配置 16
2-1實驗設備 16
2-2實驗佈置 24
2-3試驗條件 25
第3章 數據處理與分析 26
3-1試驗再現性 26
3-2分析方法 29
第4章 結果與討論 32
4-1底床剪應力時序列 32
4-2流速與底床剪應力之探討 34
4-3波高水深比之影響 36
4-4不同位置底床剪應力之變化 40
4-5 值之探討 44
第5章 結論與建議 48
5-1結論 48
5-2建議 49
參考文獻 50

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