BEM-FDM modeling of water free surface interaction with trapped air in OWC chamber for calculating generated power


Graduate School of Marine Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran


Free surface modeling plays an important role in some ocean structures design, especially in Oscillating Water Column (OWC) devices. Boundary element method (BEM) is a suitable method for free surface modeling due to its simplicity, quick solving, and low data storage requirement. In this paper, BEM was used for free surface modeling in OWC chamber and out of it. Linear kinematic and dynamic boundary conditions were used for free surface out of OWC chamber and nonlinear forms were used for free surface in the hamber. These boundary conditions were descritized by finite differences method (FDM). Also, some thermodynamics relations were applied for trapped air behavior modeling in OWC chamber. Wave specifications in Chabahar region due to its high power waves entered in programming code as input data.
The results show a good agreement with results of other researches. Also, it is concluded that Iranian sea waves have no good potential for use ordinary OWC devices, because, a little power (about 10 KW) can be extracted from an OWC, in the best point.