A new numerical model developed by IHCantabria will optimize the design of devices that capture wave energy
In places like this it is possible to place a device that captures wave energy, whose design could be improved thanks to the new numerical model developed by IHCantabria
This work confirms the usefulness of computational modeling as a fast and accurate tool for designing and optimizing wave energy harvesters
The Environmental Hydraulics Institute of the University of Cantabria (IHCantabria) has participated in the development and validation of a numerical methodology to improve efficiency and accelerate -up to 60%- calculation times to design wave energy devices based on multi-chamber oscillating water columns (OWC). This is a major breakthrough to enhance the scope of a technology that is key to harnessing the energy of the sea (wave energy).
The results of this research have been recently published in the scientific journal Ocean Engineering, under the title “Numerical analysis of multiple-chamber OWCs efficiency using a fast PTO modelling approach in OpenFOAM”. Its co-authors are the IHCantabria researchers Gabriel Barajas Ojeda and Javier López Lara, in collaboration with J.F.M. Gadelho and C. Guedes Soares, members of the Center for Marine Technology and Ocean Engineering (CENTEC) of the Instituto Superior Técnico of the University of Lisbon, Portugal.
This paper addresses one of the main challenges in the development of OWC devices: the numerical representation of the power take-off (PTO) system, which transforms wave energy into electrical energy. “Typically, these systems are difficult to simulate accurately, especially when dealing with complex configurations such as multi-chamber OWCs. In addition, traditional simulations require high computational resources and long times, which limits their application in early design phases,” explains Gabriel Barajas Ojeda, one of the co-authors of the scientific paper.
A useful methodology for the design of wave energy devices.
The objective of this research was to establish a methodology to design OWCs quickly and reliably by combining experimental models with high-fidelity numerical simulations in the OpenFOAM® environment. To this end, the authors developed a numerical surge tank with which they evaluated three ways of modeling the PTO: one based on real geometries with holes, and two using numerical regions that simulate the effect of damping by porous media or from linear momentum loss terms.
After validating the model with a double chamber configuration, the methodology was applied to a triple chamber version. The results obtained in this work show that the numerical approximations developed allow reducing the simulation times between 40 % and 60 %, without relevant loss of accuracy in the functional characterization of the chamber. Regarding energy efficiency, it was found that the triple chamber configuration does not present significant advantages over the double chamber in low damping conditions, and may even offer a lower performance (45 % vs. 60 %) in conditions of higher PTO resistance.
“This new methodology allows to explore in a more agile way, and with lower computational cost, multiple design configurations, wave conditions and potential locations for this type of devices. Despite its limitations, such as the need for calibration with physical models and the difficulty to represent details of the flow in the vicinity of the PTO, this technique represents a relevant advance for the characterization of the operation of this type of wave energy extraction devices”. This is explained by Javier López Lara.
This work continues aresearch line opened in IHCantabria, to develop numerical wave tanks to optimize different wave collection devices. The results of previous studies have been published in the scientific journal Applied Ocean Researchwhere the following articles have been published: MoonWec, OWC with PTO and FOWT.
The results of this research reinforce the role of computational modeling as a strategic tool for the design of sustainable energy systems and point to future improvements, such as the incorporation of air compressibility effects, essential to increase the accuracy of efficiency estimates under real conditions.
