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Title: Coupled Mooring Analyses for the WEC-Sim Wave Energy Converter Design Tool

A wave-energy-converter-specific time-domain modeling method (WEC-Sim) was coupled with a lumped-mass-based mooring model (MoorDyn) to improve its mooring dynamics modeling capability. This paper presents a verification and validation study on the coupled numerical method. First, a coupled model was built to simulate a 1/25 model scale floating power system connected to a traditional three-point catenary mooring with an angle of 120 between the lines. The body response and the tension force on the mooring lines at the fairlead in decay tests and under regular and irregular waves were examined. To validate and verify the coupled numerical method, the simulation results were compared to the measurements from a wave tank test and a commercial code (OrcaFlex). Second, a coupled model was built to simulate a two-body point absorber system with a chain-connected catenary system. The influence of the mooring connection on the point absorber was investigated. Overall, the study showed that the coupling of WEC-Sim and the MoorDyn model works reasonably well for simulating a floating system with practical mooring designs and predicting the corresponding dynamic loads on the mooring lines. Further analyses on improving coupling efficiency and the feasibility of applying the numerical method to simulate WEC systems with moremore » complex mooring configuration are still needed.« less
Authors:
; ; ;
Publication Date:
OSTI Identifier:
1335571
Report Number(s):
NREL/CP-5000-67554
DOE Contract Number:
AC36-08GO28308
Resource Type:
Conference
Resource Relation:
Conference: Presented at the ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering, 19-24 June 2016, Busan, South Korea
Publisher:
New York, NY: American Society of Mechanical Engineers (ASME)
Research Org:
NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States))
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Wind and Water Technologies Office (EE-4W)
Country of Publication:
United States
Language:
English
Subject:
16 TIDAL AND WAVE POWER wave energy; WEC; mooring dynamics analysis; time-domain numerical model; radiation and diffraction theory; lumped-mass model; NREL