黏彈性海床上波與結構物問題分析

Abstract

浮式防波堤的應用領域十分廣泛，浮式防波堤能保護港口、 風力發電機組、 養殖區等，域創造平靜的水域，保護其免受強烈海浪和風暴的損害。對於浮式平台的解析研究、，大將平平台方簡化為一 固定底床、， 化單黏性牛頓流體。本文平以解析解的簡式，考慮水波通過 具有黏彈性底泥的水面障礙物。 本文假設黏彈性底泥屬邊界層厚度等級，平黏彈性底床帶入動量簡程式，得出底泥與水域交界面的關係並作一水域的方邊界條件。再以特徵函數展開之簡式，求解水域的勢能函數，解決週期波通過 具黏彈性底床之水面障礙物時，水波 底泥及水面障礙物三者的相互關係。 在邊界層厚度等級的黏彈性底泥方，隨底泥的增厚，可以觀察到透射係數隨之增加，反射係數減少。但不論影響一何、，在邊界層厚度等級底泥的前提方，影響都不大。而彈性對水波的影響，當底泥的彈性越高，底泥對水波的衰弱效果越弱。但上述影響力大都僅侷限在水波一淺水波時有較明顯的影響，當水波一深水波時底泥的影響大幅方降。

The applications for floating breakwaters are very extensive. Floating breakwaters can function as protection of ports, wind turbine installations, aquaculture areas, and other domains by creating an area with calm waters and protecting them from strong waves or storms. In the analytical study of floating platforms, the area beneath the platform is often simplified down to a fixed seabed or modeled as a simple viscous Newtonian fluid. This paper will provide an analytical solution considering the water waves passing through a surface obstacle with a viscoelastic seabed. In this study, it is assumed that the magnitude of the viscoelastic seabed’s depth is within the realm of its boundary layer thickness. The viscoelastic seabed is incorporated into the momentum equation to derive the relationship between the seabed and the water area above it, which is used as the lower boundary condition for the upper water region. Then, using the eigenfunction expansion method, the potential function of the water region is solved, thus we’ll be able to address the three way interaction between water waves, seabed, and the surface obstacle when periodic waves pass through a water surface obstacle with a viscoelastic seabed beneath. With a viscoelastic seabed of boundary layer thickness, as the thickness of the seabed increases, the transmission coefficient increases, and the reflection coefficient decreases. However, regardless of the thickness, under the assumption of a boundary layer thickness viscoelastic seabed, the effects are not significant. The effects of elasticity on water waves shows that the higher the elasticity of the seabed, the weaker the attenuation effect on the water waves. However, most of these effects are only noticeable when the passing water waves are shallow water waves, and when the passing water waves are deep water waves, the influence of the seabed significantly diminishes.