DEVELOPMENT OF NUMERICAL MODEL OF FLOATING BODY WITH AIR CHAMBER FOR THE OWC-WEC USING TWO-PHASE FLOW MPS METHOD

The floating oscillating water column type wave energy converter (OWC-WEC) is highly maintainable and safe because it has no moving parts underwater. For the commercialization of the floating OWC-WEC, a method is required to analyze, in-depth, its response to waves over a wide range of wave conditions, from operational to survival conditions. In this study, the authors have developed a floating body model with an air chamber for expressing the floating oscillating water column by extending the high accuracy two-phase flow moving particle simulation (MPS) method. The MPS method is one of the particle methods used for computational fluid dynamics (CFD) simulations which can easily solve problems related to large free surface deformation and nonlinear fluid and structure interaction. Numerical and experimental investigations using the free heave decay test were conducted to confirm the validity of the developed model. A comparison of the numerical and experimental results showed that although a numerical pressure oscillation of particles increases as the power take-off (PTO) damping increased, both results generally agreed on the heave motion of the floating body, water mass height and air pressure in the air chamber, and the applicability of the proposed method was verified.