The movement of waves propagating over a horizontally submerged perforated plate with waterfilled chambers bellow the plate was investigated by using linear potential theory. The analytical solution was compared with ...The movement of waves propagating over a horizontally submerged perforated plate with waterfilled chambers bellow the plate was investigated by using linear potential theory. The analytical solution was compared with laboratory experiments on wave blocking. The analysis of the wave energy dissipation on the perforated bottom surface shows that the effects of the perforated plate on the wave motion depend mainly on the plate porosity, the wave height, and the wave period. The wave number is a complex number when the wave energy dissipation on the perforated plate is considered. The real part of the wave number refers to the spatial periodicity while the imaginary part represents the damping modulus. The characteristics of the wave motion were explored for several possible conditions.展开更多
The refraction-diffraction of surface waves due to porous variable depth has been the subject of many investigations. In the present study, we extend the boundary-value problem of impermeable varying topography to tha...The refraction-diffraction of surface waves due to porous variable depth has been the subject of many investigations. In the present study, we extend the boundary-value problem of impermeable varying topography to that of a variable depth porous seabed, which is the situation most likely to be encountered in practical prob-lems of coastal engineering. A wave-induced fluid motion is applied to the porous bottom, while the well-known linear potential theory is applied to the free-water above the bottom. Eigenfunction expansions are employed to derive the matching condition and the so-called modified dispersion relation. As a result of the porous bottom, the wavenumber becomes a complex value, of which the real part represents the spatial periodicity while the imagi-nary part refers to the energy dissipation. The characteristics of water waves over a porous bottom are studied in detail. By neglecting the non-propagating modes which only have a local effect and damp exponentially with dis-tance, we derive a mathematical model to represent the characteristics of both the wave refraction-diffraction and wave-damping. The developed model is applied to the damping problem of waves over submerged porous breakwaters.展开更多
文摘The movement of waves propagating over a horizontally submerged perforated plate with waterfilled chambers bellow the plate was investigated by using linear potential theory. The analytical solution was compared with laboratory experiments on wave blocking. The analysis of the wave energy dissipation on the perforated bottom surface shows that the effects of the perforated plate on the wave motion depend mainly on the plate porosity, the wave height, and the wave period. The wave number is a complex number when the wave energy dissipation on the perforated plate is considered. The real part of the wave number refers to the spatial periodicity while the imaginary part represents the damping modulus. The characteristics of the wave motion were explored for several possible conditions.
基金Supported by the"85"Foundation of Tsinghua University(No.092213005)
文摘The refraction-diffraction of surface waves due to porous variable depth has been the subject of many investigations. In the present study, we extend the boundary-value problem of impermeable varying topography to that of a variable depth porous seabed, which is the situation most likely to be encountered in practical prob-lems of coastal engineering. A wave-induced fluid motion is applied to the porous bottom, while the well-known linear potential theory is applied to the free-water above the bottom. Eigenfunction expansions are employed to derive the matching condition and the so-called modified dispersion relation. As a result of the porous bottom, the wavenumber becomes a complex value, of which the real part represents the spatial periodicity while the imagi-nary part refers to the energy dissipation. The characteristics of water waves over a porous bottom are studied in detail. By neglecting the non-propagating modes which only have a local effect and damp exponentially with dis-tance, we derive a mathematical model to represent the characteristics of both the wave refraction-diffraction and wave-damping. The developed model is applied to the damping problem of waves over submerged porous breakwaters.
