Experimental Study on Irregular Waves Propagating over Elliptical Shoal on a Sloping Bottom

• Main Authors: I-Chuan Huang, 黃奕銓
• Other Authors: Wen-Kai Weng
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/06927244757744876325

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 95 === An experiment in hydraulic model test, this research investigate the deformation of wave field caused by the variations in terrain when irregular wave passes through the elliptic shoal. In these experiments, we aim to discuss the phenomenon of refraction, energy concentration and focus in wave field behind the elliptic shoal while the waves in three incident angles(θ=0°、15°、30°) and two periods(T1/3=1.0、1.25sec). Therefore, the further understanding of the waves’ deformation in wave field near the elliptic shoal can be achieved. To discuss the phenomenon of refraction, energy concentration different from regular wave and irregular wave. Base on experiments, it is found that the wave upper part of the shoal enlarged, and both the energy concentration and focus were found in the back of the shoal because of the refraction. Furthermore, it indicated that phenomenon of focus form the period wave of 1.25sec is more significant than the period wave of 1.0sec. As incident angles increase, the phenomenon of focus from the period wave of 1.25sec and 1.0sec are decrease. Compare regular experiment with irregular experiment, it is found that the variation of wave height is not evident, when incident wave period is 1.0sec. The variation of wave height of regular wave is more obvious than irregular wave, when incident wave period is 1.25sec. As incident angle increases, the variation of wave height decreases. Therefore, this study applied here will be viewed as a beneficial reference to the follow-up consideration for an experiment of energy disappeared in the nearshore zone.