Ocean Energy Systems Wave Energy Modeling Task 10.4: Benchmark Study of the DTU OWC Chamber with One-Way Absorption

Abstract

This paper reports on a new milestone under the "OES Task 10Numerical modelling and verification", established to provide numerical modeling guidelines for wave energy converters. The task has been initiated by the International Energy Agency Technology Collaboration Programme for Ocean Energy Systems (OES). This study complements the studies presented in Bingham et al (2021) and Wendt et al (2019). Here we focus on small-scale (1:50) measurements of a single, Oscillating Water Column chamber mounted sideways in a long flume. The geometry of the OWC chamber is extracted from a barge-like, attenuator-type floating concept "KNSwing" with 40 chambers targeted for deployment in the Danish part of the North Sea. In addition to the traditional two-way energy extraction from an OWC, we also consider a one-way energy extraction of power with passive venting and compare chamber response, pressures and total absorbed energy between the two methods. A blind study was established for the numerical modeling, with participants applying several implementations of weakly-nonlinear potential flow theory and commercial Navier-Stokes solvers (CFD). Both compressible and incompressible models were used for the air phase.