Session: 09-05-05 Wave Energy: Oscillating Water Columns

Submission Number: 181979

Impact of Real-Gas Air Density Modeling on the Performance of Oscillating Water Column Wave Energy Converters 

Accurate modeling of Oscillating Water Column (OWC) wave energy converters necessitates precise characterization of the thermodynamic cycle within the chamber that involves an air turbine. While these systems are often simplified using ideal gas assumptions, the highly variable environmental conditions inside the air chamber, such as high humidity and air saturation, challenge this approach. These conditions suggest that real gas behavior can influences performance calculations. It is expected that the presence of humid air induces variations in the thermodynamic conditions near the air turbine, consequently modifying its operational performance and overall efficiency. The primary aim of this study is to quantify the impact of modeling the air flow as a real gas, directly comparing it against traditional ideal gas models. We focus on the evaluation of air density inside the air chamber and its subsequent effect on the air turbine's performance. Data were collected from an experimental campaign conducted at IHCantabria on a 1:13 scaled OWC model, representing the fixed breakwater installation of the Mutriku wave power plant in Spain. The scaled model consisted of an air chamber equipped with a dynamic Power Take-Off (PTO) system. Key environmental parameters, like humidity, temperature, and pressure, were measured inside the air chamber under different sea states. This experimental data was then used to apply the real gas model, calculate the resulting air density, and evaluate the differences on the performance of the wave energy converter. The findings reveal a non-negligible deviation from the ideal gas model, validating the necessity of implementing a real gas framework. This approach is essential for accurately predicting and optimizing OWC performance in real-world operating conditions.

Presenting Author: Beatrice Fenu Mondragon University

Presenting Author Biography: I am a Postdoctoral Researcher specializing in Offshore Renewable Energy. My work centers on applying advanced experimental methods and system dynamics to solve complex challenges and optimize technologies in the marine energy sector.

Authors:

Beatrice Fenu Mondragon University
Yerai Peña Sanchez Mondragon University
Cristina Casal IH Cantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria
David Blanco IH Cantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria
Ander Zarketa Mondragon University
Raul Guanche School of Naval Engineering, Technical University of Madrid (UPM)
Markel Penalba Mondragon University