۳D Numerical Modeling and Geometry Optimization of an Oscillating Water Column Device in Sloshing Conditions Using Openfoam and Genetic Algorithms

Among various types of wave energy converters, the oscillating water column (OWC) has attracted significant research attention. In this paper, a ۱:۱۰ scale OWC with dimensions of ۱۰۰×۱۰۰×۱۶۰ cm, variable inlet height and draft was numerically studied. Based on the tests conducted, it was found that the wave amplitude in the range of Caspian Sea waves decreased with the increase of wave frequency, to the extent that at the sloshing frequency, the system efficiency dropped significantly. To solve this problem, changes in the geometry of the device were studied, and numerical simulations were performed at the highest frequency using OpenFOAM software. Using Reynolds-averaged Navier-Stokes (RANS) equations, numerical simulations were performed in ۳D, two-phase, and turbulent flow conditions. Changing the geometry was initially investigated by adjusting the height of the OWC inlet duct, and then by adding an inlet at the different angles of ۰, ۲۰, and ۴۰ degrees. The results showed that by increasing the height of the inlet by ۱۰ cm while keeping the water depth and wave conditions constant, the maximum output power of the system increased by ۵۴%. However, after the optimization of the inlet duct, it was found that the best angle for an inlet duct is ۳۰°, compared to the case without an inlet, which increased the maximum output power by up to ۱۳% and slightly reduced the sloshing by more than ۵۰%.

Keywords:

Wave Energy , OWC , CFD , Sloshing , Performance