Analysis of waves interacting with submerged Poro-elastic structures

• Main Authors: Mu-Cheng Lin, 林木成
• Other Authors: Jaw-Fang Lee
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/84970722414040805362

碩士 === 國立成功大學 === 水利及海洋工程學系專班 === 93 === 　　The problems of wave propagating over submerged porous and elastic structures are studied experimentally in this thesis. Principal consideration in this study is to design model structures having porous and elastic properties which are submerged in the wave channel for the experiments. An empty box that filled with water-inflated balloons fixed at the bottom of the channel is used as the model structure. The balloons are also ballasted inside with glass balls to ensure balloons do not float in the wave fields. Three types of model structures are actually used in the experiments, a closed empty structure, a top-open empty structure, and a poro-elastic structure. Incident and reflected waves in front of the structure, transmitted waves behind the structure, as well as waves above the structure are measured, and effects of porosity and elastic structures on incident waves are then investigated. 　　To ensure the accuracy of the experiments, reflection coefficients of a submerged rigid structure are compared with analytic results. The comparisons show good consistent tendency, although the amount of experimental data are not enough. Wave forms in front of, atop, and behind the submerged poro-elastic structures are compared. And the results indicate that the submerged structures have certain damping effects on incident waves due to porosity, but the elastic effects are difficult to observe as the model scale may be too small. Wave forms for the three structure models are also compared, and the comparisons show that the top-open empty box can change the passing wave forms due to trapping effects. The present experimental study may provide useful information for further research in the future.