Experimental Studies on Wave Attenuation over an Inclined Porous Bed

• Main Authors: Xue-Ren Chang, 張學仁
• Other Authors: Hwung-Hweng Hwung
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/98773753060956277278

碩士 === 國立成功大學 === 水利及海洋工程學系專班 === 94 === This paper is aimed to investigate the relationship between wave decay and the physical properties of porous bed. To achieve this, a series of experimental tests were conducted. In these tests, a total of four types of porous material and four material thickness were adopted, then wave decay over these porous beds were measured under various wave conditions. Based on experimental results, it is observed that the wave height decreases as the dimensionless progressive distance increases. Further, the wave-decay rate increases rapidly with increasing relative thickness of the porous bed as the relative thickness is smaller than 0.2. However, if the relative thickness becomes greater than 0.2, the wave-decay rate increases only slightly with increasing relative thickness. Therefore, it is realized that waves consume more energy on the porous bed within a relative thickness of 0.2 than within the deeper part. As for the porosity, it is indicated that the wave height reduces rapidly with increasing porosity. Finally, a regression analysis was conducted and a wave-decay formula was established relating to those factors such as dimensionless progressive distance, relative thickness, and porosity.