Global performance of a square-type semi-submersible KRISO multi-unit floating wind turbine; numerical simulation vs model test

Abstract

The global performance of the Korea research institute of ships and ocean engineering (KRISO) square-type semi-submersible multi-unit floating offshore wind turbine (MUFOWT) in irregular waves is numerically simulated by using the multi-turbine-floater-mooring coupled dynamic analysis program. The developed time-domain numerical-simulation tool is extended from the FAST/CHARM3D coupled dynamics program for the single turbine on single floater. FAST has been developed by the National Renewable Energy Laboratory (NREL) for years for the single unit. Recently, KRISO has designed and studied the square-type MUFOWT, in which four 3MW wind turbines are installed at each corner of a single floater. Additionally, twenty four point-absorber-type linear-generator-based wave energy converters are set up - six wave energy converters at each side of the platform. For verification, KRISO performed a series of model tests for this MUFOWT with 1:50 Froude scale. In this paper, the MUFOWT simulation program is used to reproduce the KRISO model test results. In the fully coupled multi-turbine/hull/mooring dynamic simulations, the complete second-order difference-frequency wave forces are also included. The analysis results are systematically compared with the model test results, which shows reasonable correlation between them. ？ Copyright 2016 by the International Society of Offshore and Polar Engineers (ISOPE).