Application of Genetic Algorithm for Optimum Hydrodynamic Performance of Twin Pontoon Floating Breakwater: Fid-Bau Portal

Application of Genetic Algorithm for Optimum Hydrodynamic Performance of Twin Pontoon Floating Breakwater

Abdullah, S. F. / Fitriadhy, A.

The lateral separation ratio ( $S / D$ ) between the twin pontoons of a floating breakwater (TPFB) is one of the prominent factors that attenuate wave energy transmission and reflection. In fact, a numerical investigation of optimum TPFB $S / D$ is inevitably required. To accommodate such a requirement, a numerical optimization model of a genetic algorithm (GA) was developed to assess the optimum $S / D$ primarily through minimizing wave transmission ( $K_{t}$ ) and reflection coefficients ( $K_{r}$ ) while maximizing the energy dissipation coefficient ( $K_{d}$ ). Several parameters, such as wavelengths and $S / D$ ratios including a set of optimization criteria, were taken into account in the simulation, where the optimum solution was then selected from various populations. In addition to the current GA simulation, the optimum $S / D$ was evaluated and quantified by the values of $K_{t}$ , $K_{r}$ , and $K_{d}$ , in which the reduction of some flow parameters was visualized via computational fluid dynamics. The results revealed that the GA simulation is effectively capable of determining global trade-offs between $K_{t}$ , $K_{r}$ , and $K_{d}$ . As compared with the existing model, $K_{t}$ and $K_{r}$ decreased to less than 0.3 and 0.4, respectively, whereas $K_{d}$ increased up to 0.9, resulting in optimum TPFB hydrodynamic performance. Hence, the elaboration of this optimization algorithm can serve as a conceptual design to find an optimum $S / D$ for the twin pontoons of a floating breakwater.