Influence of heave plates on the dynamics of a floating offshore wind turbine in waves

Mello, Pedro Carvalho de; Malta, Edgard B.; Silva, Raíza O. P. da; Candido, Matheus H. O.; Carmo, Lucas Sátiro do; Alberto, Izabela F.; Franzini, Guilherme Rosa; Simos, Alexandre N.; Suzuki, Hiroki; Gonçalves, Rodolfo T.

doi:10.1007/s00773-020-00728-3

Cited by 16 publications

(7 citation statements)

References 14 publications

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“…The facility consists of a squared 14 m × 14 m × 4 m (length, width, depth) basin with flap-type wave makers distributed all around the basin, which are also responsible for active wave absorption (complete information on the ocean basin can be found in [14]). The scale factor adopted for the tests was 1:80, following previous experimental studies performed with the same model [2]. In this new set of tests, the main purposes were to evaluate the catenary anchoring systems and the effects of the wind emulated by an actuator in a software-in-the-loop (SIL) approach.…”

Section: Methodsmentioning

confidence: 99%

“…1. Following the developments presented in a previous work [2], heave plates are adopted in each column as a means to tune the natural periods of motions and to increase the viscous damping levels in resonant conditions. Tab.…”

Section: Fowt Geometry and Mooring Systemmentioning

confidence: 99%

“…The present work is part of a R&D project conducted cooperatively by the University of São Paulo and the University of Tokyo, in which different FOWT concepts were proposed and evaluated for operation in a particular site in the Brazilian coast [1][2][3]. Using the NREL 5MW turbine [17] as a reference for the wind turbine, one of the main objectives of the project was to develop, calibrate and test the performance of a computational tool designed for parametric optimization of the floater and mooring system geometries.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Seakeeping Tests of a Fowt in Wind and Waves: An Analysis of Dynamic Coupling Effects and Their Impact on the Predictions of Pitch Motion Response

Amaral¹,

Mello²,

Carmo³

et al. 2021

Preprint

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The present work highlights some of the dynamic couplings observed in a series of tests performed in a wave basin with a scaled-model of a FOWT with semi-submersible substructure. The model was moored by means of a conventional chain catenary system and an actively controlled fan was used for emulating the thrust loads during the tests. A set of wave tests comprising regular and irregular waves was done for different wave angles and wind velocities. The experimental records illustrate the main coupling effects involved and how they affect the FOWT motions in waves, especially when the floater presents a non-negligible tilt angle.. In addition, an analysis of the frequency-domain dynamic model was made in order to evaluate its ability to capture these effects properly. The influence of different modes of fan response, floater trim angles (changeable with ballast compensation) and variations of the mooring stiffness with the offsets were investigated in the analysis. Results attest that significant changes in the FOWT responses may indeed arise from coupling effects, thus indicating that caution must be taken when simplifying the hydrodynamic frequency-domain models often used as a basis for the simulation of FOWTs in waves and in in optimization procedures for the design of the floater and mooring lines.

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Section: Methodsmentioning

confidence: 99%

Section: Fowt Geometry and Mooring Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Seakeeping Tests of a Fowt in Wind and Waves: An Analysis of Dynamic Coupling Effects and Their Impact on the Predictions of Pitch Motion Response

Amaral¹,

Mello²,

Carmo³

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…The scale factor adopted for the tests was 1:80. Following the developments presented in a previous work [15], heave plates are adopted in each column as a means to tune the natural periods of motions and to increase the viscous damping levels in resonant conditions. Table 1 brings the main properties of the Jappaku FOWT in both, full and model scales (1:80).…”

Section: Fowt Geometry and Mooring Systemmentioning

confidence: 99%

“…The present work is part of an R&D project conducted cooperatively by the Universidade de São Paulo and the University of Tokyo, in which different FOWT concepts were proposed and evaluated for operating in a particular site on the Brazilian coast [14][15][16]. Using the NREL (National Renewable Energy Laboratory) 5MW turbine [17] as a reference for the wind turbine, one of the main objectives of the project was to develop, calibrate and test the performance of a computational tool designed for parametric optimization of the floater and mooring system geometries.…”

Section: Introductionmentioning

confidence: 99%

Seakeeping Tests of a FOWT in Wind and Waves: An Analysis of Dynamic Coupling Effects and Their Impact on the Predictions of Pitch Motion Response

Amaral

Mello

Carmo

et al. 2021

JMSE

Self Cite

View full text Add to dashboard Cite

The present work highlights some of the dynamic couplings observed in a series of tests performed in a wave basin with a scaled-model of a Floating Offshore Wind Turbine (FOWT) with semi-submersible substructure. The model was moored by means of a conventional chain catenary system and an actively controlled fan was used for emulating the thrust loads during the tests. A set of wave tests was performed for concomitant effects of not aligned wave and wind. The experimental measurements illustrate the main coupling effects involved and how they affect the FOWT motions in waves, especially when the floater presents a non-negligible tilt angle. In addition, a frequency domain numerical analysis was performed in order to evaluate its ability to capture these effects properly. The influence of different modes of fan response, floater trim angles (changeable with ballast compensation) and variations in the mooring stiffness with the offsets were investigated in the analysis. Results attest that significant changes in the FOWT responses may indeed arise from coupling effects, thus indicating that caution must be taken when simplifying the hydrodynamic frequency-domain models often used as a basis for the simulation of FOWTs in waves and in optimization procedures for the design of the floater and mooring lines.

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Bearing Capacity of Cylindrical Caissons in Cohesive-Frictional Soils Using Axisymmetric Finite Element Limit Analysis

2022

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This paper investigates the use of stability factors for estimating the ultimate bearing pressures on cylindrical caissons in cohesive-frictional soils. Rigorous upper and lower bound limit analyses with finite elements in axisymmetric (AX) condition are used for a series of numerical studies. The bearing capacity factors (Nc0, Nq0 and Nγ0) for a surface circular footing are firstly revisited. This is followed by a study on the effect of caisson’s embedded depth ratio (L/D). A comprehensive set of depth factors (Fcd, Fqd and Fγd) is then reported as a function of caisson’s embedded depth ratio (L/D) and soil internal friction angle (ϕ). The obtained results are compared with published solutions in the literature. Several examples are given to validate the principal of superposition as well as to illustrate on how to use the produced factors to estimate the ultimate bearing pressures on cylindrical caissons in cohesive-frictional soils. The study should be of great interests to practitioners.

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Influence of heave plates on the dynamics of a floating offshore wind turbine in waves

Cited by 16 publications

References 14 publications

Seakeeping Tests of a Fowt in Wind and Waves: An Analysis of Dynamic Coupling Effects and Their Impact on the Predictions of Pitch Motion Response

Seakeeping Tests of a Fowt in Wind and Waves: An Analysis of Dynamic Coupling Effects and Their Impact on the Predictions of Pitch Motion Response

Seakeeping Tests of a FOWT in Wind and Waves: An Analysis of Dynamic Coupling Effects and Their Impact on the Predictions of Pitch Motion Response

Bearing Capacity of Cylindrical Caissons in Cohesive-Frictional Soils Using Axisymmetric Finite Element Limit Analysis

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