本文旨在探討初始平坦沙層底床受波浪作用逐漸形成沙漣時,利用流場可視化經由影像處理擷取瞬時沙面曲線,探討沙漣開始生成、與達到成熟漣長、成熟漣高所需造波次數,利用Shields(1936)所提出之包含流體特性、底床沙粒特性與流場相關特性之近似可動參數之無因次參數Ψ來推估﹔分別提出所需時間之預估經驗式。且發現沙漣始生成至沙漣漣高成熟所需時間約為沙漣始生成至沙漣漣長成熟所需時間的1.5倍。將本次實驗的結果綜合前人之實驗值,提出兩條由波浪條件及底質特性來估算成熟漣長λ/sub m/與成熟漣高η/sub m/,適用於實驗室的兩條經驗式。 In this study, the flow visualization technique is utilized to obtain an elementary knowledge about the transient processes until mature sandy ripples being formed. The mature wavelength and wave height of ripples are also made by using a/D/sub 50/ and Shields parameter.PSI.. We analyzed data of ripples obtained in wave flumes and combined the former researcher's results in order to achieve a reasonable experience function. The experimental relationships between the ripple geometry and hydraulic parameters were derived.
關聯:
第二十屆海洋工程研討會論文集=Proceedings of the 20th Ocean Engineering Conference in Taiwan, R.O.C.,頁515-522