Application of a Phase-Resolving Wave Model to Enhance the Capabilities of a Wave Energy Converter Simulation Tool

Industry-specific tools to analyze and optimize the design of wave energy converters (WECs) and associated power systems promote a more rapid and cost-efficient development of devices and thus advance the WEC industry and Blue Economy. Key to this effort is to simulate realistic wave climates that are phase-resolved and reflect operational conditions. In this study, we run the phase-resolving wave model FUNWAVE-TVD to generate directional waves at the PacWave South site where future wave energy converters are expected to be installed for testing. The model is forced with climatological frequency-direction wave spectra obtained from a Simulating Waves Nearshore (SWAN) simulation, conducted for a separate resource characterization study. FUNWAVE-TVD time-series of sea-surface-elevation at multiple virtual WEC locations in an array are then used in WEC-Sim, a time-domain numerical model to simulate the hydrodynamic response and estimate power output for each device. Two broad cases are presented corresponding to mean wave climates during warm months (March through August) and cold months (September through February) off the Oregon coast. The spatial influence of wave propagation on the potential power output of the virtual WEC array is explored. The power response is characterized from multiple realizations of the offshore wave climate. For comparison, WEC-Sim is also run with random-phase time-series derived directly from SWAN directional spectra by means of random superposition of wave components, which are not necessarily consistent due to the linear assumption implicit in this method.