本文應用質點影像測速儀 (PIV) 量測波浪作用下潛堤附近流場與渦流強度的變化。試驗於二維試驗水槽中進行，利用試驗所量測到的流速資料可以求得渦流強度與渦流能量。本文在不同底床坡度的試驗配置下，探討單列以及雙列潛堤的流場特性，並且改變雙列潛堤的間距，以瞭解潛堤間距對流場變化的影響。試驗結果發現，雙列潛堤的試驗配置，渦流強度大小不會隨著坡度變大而增加，而是受到反射率大小的影響，若反射率大，則進入擺設潛堤區域內的波浪能量就減少，故結構物周圍所能滯留的能量就小，潛堤周圍所發生的渦流強度就變小。而由波浪通過斜坡底床上單列潛堤及雙列潛堤的試驗結果亦可發現，坡度越陡俊，結構物表面所發生的渦流會有往向岸側移動的趨勢。

　　Present research uses Particle Image Velocimetry (PIV) to measure the changes of the velocity and the vorticity fields around the submerged breakwaters, as influenced by the wave interactions. The experiment is conducted in a two-dimensional experimental tank. The measured current velocities are used to calculate the vorticity and the vortex energy. The study addresses changes in the flow characteristics associated with a single submerged breakwater and the double submerged breakwaters with different bottom slopes and different spans of the double submerged breakwaters. According to the results obtained from the experiments, in presence of double submerged breakwaters, the vorticity doesn’t increase with the increasing of bottom slope; however, the wave reflection plays an important role. If the reflection is large, the wave energy entering into between the submerged breakwaters remains small, so that the structures do not held much energy from the induced waves, and therefore, the vortices around the submerged breakwater also become small. The vortex formed on the front surface of the submerged breakwaters was found to have a tendency of moving towards the lee side.

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