Coastal Protection & Wave Energy Devices
WECPOS – Wave Energy Coastal Protection Oscillating System
This material was contributed by MEDUS (Maritime Engineering Division University of Salerno) - Department of Civil Engineering, Italy
In recent years, the interest in developing new technologies to produce energy with low environmental impact by using renewable sources has grown exponentially all over the world. Devices that derive electricity from the sea (currents, waves, etc.) are of particular interest and can be modeled accurately with FLOW-3D.
Another important environmental aspect is the protection of the coast from sea waves. Taking both wave energy and coastal protection under consideration, researchers at the University of Salerno have developed a submerged system called, WECPOS (Wave Energy Coastal Protection Oscillating System). WECPOS is designed to be located in relatively shallow depths, and can be used simultaneously for both electricity generation and for the coastal protection using the oscillating motion of the water particles.
Geometry of the WECPOS structure
Simulation results of WECPOS structure using FLOW-3D
Simulating the Wave Energy Device-WECPOS
The single element constituting the system is realized by a fixed base and three movable panels that can fluctuate in a fixed angle. The waves interact with the panels generating an alternative motion which can be exploited to produce electricity.
At the same time, the constraint movement imposed for the rotation of the panels is a barrier to the wave propagation phenomena, triggering the breaking in the downstream part of the device. So the wave energy will be dissipated obtaining a positive effect for coastal protection.
Using FLOW-3D it was possible to evaluate the hydrodynamic interactions that occur between a regular wave, with different height and period characteristics.
The RANS equations, coupled with the RNG turbulence model and the General Moving Objects (GMO) model, have been integrated on a three-dimensional channel (90.0 x 6.0 x 8.0 m), using a numerical domain made of two mesh blocks: a general one containing the entire domain (cell size = 0.30 cm) and a localized one on the device (cell size = 0.10 cm).
A 2D view in FLOW-3D shows turbulent energy of wave interactions with the WECPOS
With the results, by assessing the rotational angle, angular velocity, hydraulic torque of the individual panel it has been possible to estimate the potential energy production. A Matlab/Simulink model has been built to estimate the production of electric energy by means of an oleodynamic system consisting of a piston and a turbine coupled with an electric generator.
By estimating characteristic parameters of the wave motion (zero-moment wave height Hmo, transmission coefficient Kt and the average free-surface elevation), the behavior of the WECPOS device has been analyzed for its ability to dissipate wave energy dissipation, which is imperative for coastal protection.