Analisis Hidrodinamik pada Oscillating Water Column (Owc) dengan menggunakan Eigenfunction Expansion Method dan Software Nemoh

Abstract

Indonesia is a maritime country that has great potential to utilize sea wave energy as a renewable energy source. However, the development of technology to utilize wave energy in Indonesia is currently still not optimal even though it is quite profitable. Modeling of wave energy conversion technology from a hydrodynamic aspect needs to be done to get a structure that can compete and can produce electrical energy optimally. This study aims to model the Oscillating Water Column (OWC) device in the form of a three-dimensional cylinder using the Eigenfunction Expansion Method and NEMOH software and compare the two modeling results, as well as calculate the hydrodynamic efficiency of wave energy that can be absorbed by the OWC device in several ranges of wave conditions. Modeling is carried out by two methods, namely analytically with the Eigenfunction Expansion Method and numerically with the Boundary Element Method using NEMOH software. The modeling results with analytical calculations and NEMOH software show good value suitability, such as added mass, radiation damping, and Response Amplitude Operator (RAO). The parameters of standing wave modes exert the most significant influence when near the OWC structure and it is important to take them into account in analyzing the efficiency of OWC to obtain optimal OWC performance. The results of hydrodynamic efficiency show good results, where the greatest efficiency occurs when resonance and efficiency decrease along with the increase in wall thickness of OWC