Session: 05-05-02 Aquaculture and Related Technology II

Paper Number: 107202

107202 - Development of Numerical Model of Floating Body With Air Chamber for the Owc-Wec Using Two-Phase Flow Mps Method 

Ocean renewable energy resource utilization contributes to achieve a decarbonized society. Among wave energy converter, the floating oscillating water column type (F-OWC) is recognized as a highly maintainable and safety because it has no moving parts underwater. Some actual sea tests had been carried out by prototype models. However, the power generation cost is high because high equipment cost and low power generation efficiency, and this a major challenge for its commercialization.

In order to reduce the cost, it is important to develop a floating body shape that absorbs wave energy with high efficiency during an operation in normal sea state, as well as to evaluate of its safety during in survival condition for optimal design that reduces manufacturing and installation costs.

Therefore, a method is required to analyze in detail the response of a F-OWC in waves under a wide range of wave conditions, from operational condition to survival condition.

The authors have focused on the Moving Particle Simulation (MPS) method, which is one of the particle methods, CFD, that can easily solve large free surface deformation and nonlinear fluid and structure interaction problems. Authors have developed a two-phase flow MPS method for wave response analysis of shore-based OWCs and clarified its applicability.

In this study, authors developed a floating body model with an air chamber for expressing the F-OWC by extending the two-phase flow MPS code, and numerical and experimental investigations by a free decay test were conducted to confirm the validity of the developed model.

Comparison of numerical results with experimental ones showed that both of results was generally agrees about heave motion of the floating body, water mass height and air pressure in the air chamber, and its basic applicability was clarified. On the other hand, a numerical pressure oscillation of particles increases as the PTO damping increases.

In the future, we will study parameter settings and developing numerical stabilization algorithm for stable calculations, and apply the developed model to investigate numerical hydrodynamic performance of F-OWC in waves.

Presenting Author: Yutaro Sasahara Tokyo University of Marine Science and Technology

Presenting Author Biography: Yutaro Sasahara is an assitant professor of Department of Marine System Engineering of Tokyo University of Marine Science and Technology.
His work focuses specifically on development of a high efficiency oscillating water column type wave energy converter using CFD.

Authors:

Yutaro Sasahara Tokyo University of Marine Science and Technology
Mitsuhiro Masuda Tokyo University of Marine Science and Technology