Numerical Analysis of Wave Transformation due to Trench in the Uneven Sea Bottom

• Main Authors: Jung-Kuei Lee, 李榮貴
• Other Authors: Wen-kai Weng
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/35099745252376746342

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 95 === This study investigates wave transformation for wave propagating through the trench using of boundary element method. A trench in a constant depth is first studied and compared with previous theoretical results. Bragg resonance is also investigated for the case of multi trench with the same size and interval, placed up on a constant water depth region. It is found that Bragg resonance takes place as the spacing of the trench is half of the wave length of propagating waves. Finally, a trench on the uneven sea bottom is also investigated, and found the reflection and transmission coefficient. The results show that the reflection coefficient approaches a constant value, and the transmission coefficient is over the value of 1.0 when the incident wave passed through the region. The conservation of wave energy has been confirmed after the transmission coefficient is modified by means of group velocity of wave.