本計畫主要針對波浪作用下,離岸潛堤背後所發生的渦流行為進行研究。文中係利用第二年計畫所發展的延伸拋物線型波浪模式 (Hsu and Wen, 1999) 計算波場,並結合幅射應力之觀念計算堤後近岸流場。本文變換波浪入射條件、潛堤離岸距離、潛堤高度及所在位置水深,探討堤體背後之環流特徵半徑與強度,根據模式計算結果歸納環流特徵與影響因素之關係。 The vortex behavior behind the submerged breakwaters due to waves attack in the nearshore region is investigated. The extended time-dependent mild-slope equation (Hsu and Wen, 1999) is employed to calculate wave transformation in the nearshores region. The wave-induced nearshore current is predicted through the governing equation that incorporates the radiation stresses. We change different conditions of wave incidence, submerged breakwater's offshore distance, length, height and depth in the water. We use these conditions to investigate the characteristics of nearshore vortex radius and strength. Following the results, we can get the relations between the nearshore vortex patterns and influences factors.