Wave Damping Characteristics of Deeply Submerged Breakwaters

Interaction of non-breaking regular waves with a periodic array of artificial porous bars

“…It is worthwhile to mention that in the case of K p /h 2 = 9.5 Â 10 À 7 , the computed friction coefficient is around 1.6, varying slightly depending on the wave length, while in the other two cases of K p / h 2 = 2.2 Â 10 À 6 and 3.45 Â 10 À 6 the computed friction coefficient is around 1.2 and 1.0, respectively. These results agree with the study of Twu et al (2001) in which it was claimed that the wave damping characteristics of a submerged structure depends only slightly on the friction coefficient if the friction coefficient is greater than 1.0 and e z 0.3.…”

“…Note that they did not elaborate on the role played by the porosity of the breakwater in reflection and transmission. According to Twu et al (2001), the porosity of the submerged breakwater contributes more to the wave damping than the friction coefficient. In this paper the interaction of non-breaking regular waves with a periodic array of porous bars will be investigated relating to the porosity and several other factors.…”

“…Therefore, no wave dissipation takes place in the process of wave and structure interaction in these models and high reflection from the structure means low transmission through the structure-this phenomenon may not be valid for porous bars. It was suggested by Yu and Chwang (1994) and Twu et al (2001) in their studies on submerged breakwaters that material porosity plays an important role in determining the reflection and transmission coefficients. Mase et al (1996) developed coupled parabolic equations to compute surface waves propagating over a group of porous submerged breakwaters.…”

Interaction of gravity waves with bottom-standing submerged structures having perforated outer-layer placed on a sloping bed

“…Using mild-slope approximation, Mendez et al [23] studied the effect of wave reflection and energy dissipation on various physical quantities such as mass flux, energy flux, radiation stress, and mean water level. Using eigenfunction expansion method, Twu et al [24] studied the transmission of water waves over deeply submerged breakwater. They have shown that the breakwater structures with more slices reduce the wave transmission on the lee side of the structure.…”

The Effect of Porosity of Submerged and Emerged Breakwater on Wave Transmission

“…Heikal and Attar examined the efficiency of an impermeable, vertical thin submerged breakwater sited on sloping impermeable bed experimentally and numerically by using the Eigen Function Expansion method [4]. Twu et al studied theoretically, using the Eigen Function Expansion method, the problem of wave transmission over a rectangular and vertically stratified with multi-slice porous material [5]. Stamos and Hajj developed a new method to separate incident and reflected wave components [6].…”