Comparison of Experimental and Numerical Model Results of Oscillating Water Column System Under Regular Wave Conditions

Abstract

Wave energy has attracted signifcant attention because of its non-polluting nature, environment friendliness, low operational cost and simple maintenance procedures compared to other clean energy sources. In this study, it was attempted to optimize an oscillating water column (OWC) wave energy converter, which is constructed on a shoreline. This study proposed numerical and physical models for the optimization of the OWC-type wave energy converters. Sixty-four experimental sets were carried out by a piston-type wave maker in order to investigate the infuence of wave parameters, water depth and geometry of coastal structures on the efciency of the system. A numerical model of the experimental model sets of the OWC system was performed by a software called Flow 3D. Intersection with a water–air in the software for the determination of the free surface of a volume of fuid method is used. K–ε turbulence model was used for turbulent model. The drag coefcient, surface roughness, pipe roughness and surface tension were used for calibration. It is observed that the numerical model results follow the experimental model results. The numerical and the experimental model results were compared with each other by taking into consideration the mean squared error, coefcient of determination (R2 ) and Nash–Sutclife efciency (NSE) as performance evaluation criteria. According to the test results, the NSE value was obtained to be 0.97 and this value also shows very good agreement between numerical results and experimental results. The experimental results showed that wave parameters are strongly related to the outfow of air from the chamber, whereas the slope angle of the chamber is inversely related. Considering diferent water depths, the various wave series and angle of the chamber, maximum efciency of OWC was obtained at 50 cm, wave series No. 1 and an angle of 40°, respectively.