Damping Characteristics of Solitary Wave Propagating over Sandy Bed in Shallow Water

Abstract

To analyze the damping characteristics of solitary waves over a sandy bed, a numerical wave tank (NWT) with non-reflected wave generation system for solitary waves was used in this study. For the validity and effectiveness of NWT used, it was compared with the theoretical results to show damping phenomena of solitary wave passing over a porous bed. It is shown that the applied NWT in this study is applicable to the numerical analyses of a solitary wave propagation over a porous bed. Using the results obtained from NWT, the solitary wave amplitudes were reduced as the wave propagates over a sandy bed. And the solitary wave attenuations became more serious as the vorticity and turbulence kinetic energy were increased by the velocity difference around the face of a sandy bed. As well, the solitary wave attenuations became more serious with higher amplitude ratio to water depth when the solitary wave propagates over a sandy bed. In addition, the effects of effective wavelength on the damping of solitary waves over a sandy bed is discussed.