Experimental and Numerical Study of Hydrodynamic and Stability Analysis of Barge-Type FOWT Platform

Abstract

The global wind energy industry has developed for over 30 years However offshore wind power within 50 to 60 meters of water depth is gradually saturated Wind power installations are from nearshore to offshore by degrees With an increase in water depth and cost the fixed-bottom structure is not a good choice for offshore wind So the floating offshore wind industry has become the center stage of renewable energy The floating offshore wind turbines (FOWT) platform can be classified as three main types according to reaching stability In addition to three types a barge-type floating offshore wind turbine platform which is a new concept which moon pool is used to reduce the motion of platform In this study a floating barge platform with a moon pool supports NREL 5MW wind turbine with mooring systems at a water depth of 50 meters ANSYS AQWA is used to analyze the hydrodynamic performance and stability of platform Experiments in a wave basin (60m*7m*1m) were conducted at Tainan Hydraulics Laboratory (THL) National Cheng Kung University (NCKU) The model is a 1:64 scaled barge platform and the turbine is scaled down from NREL 5MW wind turbine The three test conditions of platform were simulated including the free decay test regular wave test irregular wave test with wind operation and parking The experiment is conducted to get the natural period through free decay test; The numerical simulation compares with the 1:64 scaled experiment to observe the motions and Response Amplitude Operator (RAO) of surge heave and pitch motions on the barge platform with moon pool; Then the optimized platform with an additional heave plate is designed to compare to original platform without a heave plate to improve the stability From the obtained result an optimized barge-type FOWT platform is proposed in this study

Date of Award	2020
Original language	English
Supervisor	Ray-Yeng Yang (Supervisor)