Experimental Study on the Characteristics of Vortices Induced by a Internal Solitary Wave Propagating over a Submerged Vertical Plate

• Main Authors: Ang Lin, 林昂
• Other Authors: 林呈
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/78752514555896990931

碩士 === 中興大學 === 土木工程學系所 === 95 === The purpose of the study is to understand flow field induced by the internal solitary wave propagating over a submerged vertical plate model. A submerged vertical plate was used for simplified model. The experiments were conducted at the same density ratio (ρ1/ρ2 = 1.021) and the same thickness ratio of the upper and lower layers (depression: h1/h2 = 1/3; elevation: h1/h2 = 3). The same wave condition of the stable internal solitary wave is L equals 15 cm and η0 equals 10 cm. The high-speed camera was used to capture the image of flow field. The particle tracing method was utilized for flow visualization. The advanced particle image velocimetry was first used to quantitatively observe two different type internal solitary waves in absence of obstacle. The characteristics of vortices induced by a internal solitary wave propagating over a submerged vertical plate were investigated in detail. The vortex at the upstream side was induced by a internal solitary wave of depression. The vortex strength is related to the height of the vertical plate. On the other hand, the vortex at the downstream side was triggered by a internal solitary wave of elevation. The velocity of the overtopping flow increases with the increase of the height of the vertical plate. The vortex strength also increases with the increase of the velocity of the overtopping flow behind the vertical plate. Base on the measured velocity and vortex data, the vortex circulation was analyzed with non-dimensional time. The variation with time of the vortex circulation induced by a internal solitary wave propagating over a submerged vertical plate was observed.