Hydrodynamic performance of cylindrical floating breakwater in waves

Abstract

Attenuating waves by simple prismatic structures are increasingly recognised for coastal protection. Yet, evaluating their performance as good attenuators inevitably requires a reliable approach to adequately capture the dynamic interaction between waves and structure. This paper presents a prediction on hydrodynamic properties of pile-restrained cylindrical floating breakwater using computational fluid dynamics (CFD) approach. Several parameters for the effects of relative width (/) and relative draft (/) of the floating breakwater on the coefficient of transmission, reflection, and energy dissipation have been simulated using Flow3D. A wave boundary is assigned to give an insight into the regular and random wave effects to the parameters used in the simulation. The result revealed that the wave absorbing effect of CFB is apparently good, especially in high regular waves that considerably suppress the wave transmission. The higher energy dissipation than reflection characteristics suggests that the breakwater behaves effective as wave dissipator, especially for short waves. This attributed to the stiffness effect and in-plane damping across the vertical cage. From the practical views, the installation of the breakwater system into floating bridge or docks with limited rolls is satisfactory for perimeter protection specifically in the coastal zone of peninsular Malaysia.

Experimental Study on Wave Transmission Coefficient of Double Cylindrical Floating Breakwater in a Wave Basin

“…In Figure 6, the spacing between DCFB structures was designed to have 0.2 m size between the floating cylinders, but between the TCFB units there was no gap. In Figure 7, the size between the floating cylinders have been increased to 0.6 m, while the gap between the DCFB units was increased to 0.5 m. The experimentation in Figure 6 was based the condition as layout in the in Abdullah et al, [12]. The experimentation set up in the Figure 7 was to explore the possibility of improving the wave transmission coefficient by increasing the size between the floating cylinders and to introduce a gap between the TCFB units.…”

“…Therefore, the introduction of DCFB into actual coastal applications can be seen as a desirable solution to the potential environmental hazards in coastal areas [11]. Determining the wave transmission coefficient under different environmental conditions are necessary to identify the most optimum DCFB design and arrangement to effectively protect coastal areas from potential wave damages [12]. Successful application of floating breakwater to mitigate coastal damage not only contribute to the progress in coastal engineering but also improves safety and sustainability of community environments [13].…”

“…The primary aim is to have an in-depth comprehension on the structure and its functions, as well as to evaluate the structure performance by investigating the wave transmission coefficient. The current study has two objectives: firstly, to quantify the wave transmission coefficient of DCFB with different spacing between the cylinders (0.2m and 0.5m respectively) [12]; and secondly, to compare the wave transmission coefficient of DCFB systems without gap between the DCFB units and with a 0.5m gap between the DCFB units. The experiment was carried out in a wave basin with a wave paddle to generate waves and wave gauges to quantify the wave transmission coefficient.…”

Numerical Analysis of Velocity Magnitude on Wave Energy Converter System in Perforated Breakwater

“…1). After the model geometry of a perforated breakwater slope has been created, numerical modeling was carried out using one of the Computer Fluid Dynamic (CFD) programs, namely FLOW-3D (Abdullah et al, 2017;Setyandito et al, 2020).…”

Optimized modelling on lateral separation of twin pontoon-net floating breakwater

“…Similarly, Syed and Mani [14] studied a multiple interconnected pontoon with S/D equal to 0.50 to obtain the same wave attenuation. Recently, a TPFB with mesh cage and suspended balls had been investigated by some authors in moored [9] and pile restrained [15] conditions. In their study, the new type of floating breakwater exhibits a better performance in long waves, however the variable trends of are mostly higher than 0.5.…”