CFD design-load analysis of a two-body wave energy converter

Journal Article · 02 April 2019 · Journal of Ocean Engineering and Marine Energy

DOI: https://doi.org/10.1007/s40722-019-00129-8 · OSTI ID:1515194

Coe, Ryan G.  ^[1]; Rosenberg, Brian J. ^[2]; Quon, Eliot W. ^[3]; Chartrand, Chris C. ^[1]; Yu, Yi-Hsiang ^[3]; van Rij, Jennifer ^[3]; Mundon, Tim R. ^[2]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2. Oscilla Power, Inc., Seattle, WA (United States)
3. National Renewable Energy Lab. (NREL), Golden, CO (United States)

Wave energy converters (WECs) must survive in a wide variety of conditions while minimizing structural costs, so as to deliver power at cost-competitive rates. Although engineering design and analysis tools used for other ocean systems, such as offshore structures and ships, can be applied, the unique nature and limited historical experience of WEC design necessitates assessment of the effectiveness of these methods for this specific application. This paper details a study to predict extreme loading in a two-body WEC using a combination of mid-fidelity and high-fidelity numerical modeling tools. Here, the mid-fidelity approach is a time-domain model based on linearized potential flow hydrodynamics and the high-fidelity modeling tool is an unsteady Reynolds-averaged Navier-Stokes model. In both models, the dynamics of the WEC power take-off and mooring system have been included. For the high-fidelity model, two design wave approaches (an equivalent regular wave and a focused wave) are used to estimate the worst case wave forcing within a realistic irregular sea state. These simplified design wave approaches aim to capture the extreme response of the WEC within a feasible amount of computational effort. When compared to the mid-fidelity model results in a long-duration irregular sea, the short-duration design waves simulated in CFD produce upper percentile load responses, hinting at the suitability of these two approaches.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Oscilla Power, Inc., Seattle, WA (United States); National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Renewable Energy. Water Power Technologies Office; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Renewable Energy. Wind Energy Technologies Office; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Wind and Water Technologies Office (EE-4W)
• Grant/Contract Number: NA0003525; EE0007346; AC36-08GO28308
• OSTI ID: 1515194
• Alternate ID(s): OSTI ID: 1525306
• Report Number(s): SAND-2019-4731J; NREL/JA-5000-72447; 675051
• Journal Information: Journal of Ocean Engineering and Marine Energy, Vol. 5, Issue 2; ISSN 2198-6444
• Publisher: Springer International PublishingCopyright Statement
• Country of Publication: United States
• Language: English