This paper addresses the hydraulic performance of double curtain wall breakwaters (with the seaward perforated) based on the recent improved MPS model by Wang et al. (2017). The effects of structural parameters on the functions of breakwaters were investigated under different wave conditions, e.g., the porosity, submerged depth, chamber width of breakwaters. The numerical results were verified by the corresponding experimental data, and the comparisons showed that the present MPS model had a good performance on the estimation of wave transmission, reflection, and energy dissipation coefficients of double curtain wall breakwaters.
Noticeably, activities and development with regard to safety, economy, and environment in coastal areas have continued to increase in recent years. For protecting the structures on harbor and coastal areas, it would be sufficient to provide barriers, such as double curtain wall breakwater with the perforated seaward wall and an impermeable rear wall, to reduce wave attenuation and wave energy dissipation during waves propagating.
Traditional breakwaters, such as the rubble mound breakwater and the gravity wall breaker, etc., are effective for increasing wave damping but the construction costs are higher, especially in the deepwater region. In addition, these types of coastal structures prevent the circulation of water, cause severe erosion of sea beds, and deteriorate the water quality near the coast. Therefore, the partially immersed breakwater (curtain wall breakwater) was developed and investigated as a novel coastal protection structure. In the study of curtain wall breakwater, the estimations of wave transmission, reflection, and energy dissipation play a vital role in the understanding of the hydraulic performance of this structure.
For many years, several researchers have presented the experimental, theoretical or numerical investigation on the hydraulic performance of curtain wall breakwater. As a consequence, the researches on hydraulic performance and loading are limited, and most work dates back to the Ursell (1947) and Wiegel (1960) who examined analytically and experimentally the partial transmission and reflection of deep water waves from the barriers respectively. Reddy and Neelamani (1992) carried out experimental studies to investigate the effect of regular wave steepness on the transmitted coefficient of curtain-types breakwaters in deep water. Also, Kriebel (1993), Abul-Azm (1993), Isaacson et al. (1998), Isaacson et al. (1999), Cox et al. (1999), Suh et al. (2007), Rageh and Koraim (2010), Liu and Li (2011), Jing (2009), Ahmed et al. (2014) investigated the hydraulic performance of fully and partial immersed, single or double rows of slotted/perforated breakwaters by experimental and numerical with different analytical models such as eigenfunction expansion, boundary integral equation, etc. Most of these studies focused on the reflection coefficient of slotted/perforated wall structures. Furthermore, a numerical simulation model based on the Navier-Stokes (N-S) equation has become a common approach to solving these types of complex practical problems. Hence; wave motion of an incompressible Newtonian fluid can be described accurately by the continuity and Navier-Stokes equation (Van Gent et al., 1994).
