OC6 Phase Ib: Validation of the CFD predictions of difference-frequency wave excitation on a FOWT semisubmersible

Wang, Lu; Robertson, Amy; Jonkman, Jason; Yu, Yi-Hsiang; Koop, Arjen; Nadal, Adrià Borràs; Li, Haoran; Bachynski‐Polić, Erin E.; Pinguet, Romain; Zeng, Xinmeng; Zhou, Yang; Xiao, Qing; Kumar, Rupesh; Sarlak, Hamid; Ransley, Edward; Brown, Scott; Hann, Martyn; Netzband, Stefan; Wermbter, Malwin; López, Beatriz Méndez

doi:10.1016/j.oceaneng.2021.110026

Cited by 31 publications

(23 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 SST = shear stress transport. 3 The maximum difference in P is not given as percentages because P is very close to zero for heave decay.…”

Section: Surge Dampingmentioning

confidence: 99%

“…Previously in OC6 Phase I, we focused on using CFD to obtain estimates of the wave diffraction loads on the OC6-DeepCwind semisubmersible in a fixed condition, especially the nonlinear, low-frequency loads that potentially excite the surge and pitch resonance motion of a semisubmersible FOWT [2][3][4]. Tuning the engineering models also requires knowledge of the motion-damping characteristics of the floater, which are strongly influenced by viscous effects (see [5]); therefore, we now focus on the validation of CFD simulations of the free-decay motion of the OC6-DeepCwind semisubmersible.…”

Section: Introductionmentioning

confidence: 99%

“…Adaptive time step is based on the Courant number, Co 2. Approximately corresponds to the first mesh refinement zone of Table5 3. Approximately corresponds to the first mesh refinement zone of Table6 4.…”

mentioning

confidence: 99%

See 2 more Smart Citations

OC6 Phase Ia: CFD Simulations of the Free-Decay Motion of the DeepCwind Semisubmersible

et al. 2022

Self Cite

View full text Add to dashboard Cite

Currently, the design of floating offshore wind systems is primarily based on mid-fidelity models with empirical drag forces. The tuning of the model coefficients requires data from either experiments or high-fidelity simulations. As part of the OC6 (Offshore Code Comparison Collaboration, Continued, with Correlation, and unCertainty (OC6) is a project under the International Energy Agency Wind Task 30 framework) project, the present investigation explores the latter option. A verification and validation study of computational fluid dynamics (CFD) models of the DeepCwind semisubmersible undergoing free-decay motion is performed. Several institutions provided CFD results for validation against the OC6 experimental campaign. The objective is to evaluate whether the CFD setups of the participants can provide valid estimates of the hydrodynamic damping coefficients needed by mid-fidelity models. The linear and quadratic damping coefficients and the equivalent damping ratio are chosen as metrics for validation. Large numerical uncertainties are estimated for the linear and quadratic damping coefficients; however, the equivalent damping ratios are more consistently predicted with lower uncertainty. Some difference is observed between the experimental and CFD surge-decay motion, which is caused by mechanical damping not considered in the simulations that likely originated from the mooring setup, including a Coulomb-friction-type force. Overall, the simulations and the experiment show reasonable agreement, thus demonstrating the feasibility of using CFD simulations to tune mid-fidelity models.

show abstract

“…2 SST = shear stress transport. 3 The maximum difference in P is not given as percentages because P is very close to zero for heave decay.…”

Section: Surge Dampingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

OC6 Phase Ia: CFD Simulations of the Free-Decay Motion of the DeepCwind Semisubmersible

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…This includes the uncertainties in the wave measurements dictated by the performance and installation of the wave probes, but also the contributions from spurious wave components present in the basin. The uncertainty levels in the combined wave loads on all three columns (see Table 7 in [7]) are low for some cases and higher for others, ranging from 5% to 25%. Higher uncertainties in the wave loads (around 20%) were found for bichromatic waves B2 and B5, which involves wave components with periods close to 9.6 s and 7.4 s full scale.…”

Section: Uncertainty Analysismentioning

confidence: 96%

“…test individual components (columns and heave plates) of a semisubmersible (alone and in combination) to better understand how the hydrodynamic loading changes for structures in proximity, 2. obtain detailed, distributed load information on the structure, and 3. perform bichromatic-wave cases to facilitate low-frequency load validation. Investigation of the nonlinear hydrodynamic loading on floating wind semisubmersibles across the OC5 (https://a2e.energy.gov/projects/oc5 accessed on 24 September 2021) [1] and OC6 (https://a2e.energy.gov/projects/oc6 accessed on 24 September 2021) projects [4][5][6][7]. (Photos for OC5 Phase II and OC6 Phase Ia by Amy Robertson, NREL.…”

Section: Introductionmentioning

confidence: 99%

OC6 Phase Ib: Floating Wind Component Experiment for Difference-Frequency Hydrodynamic Load Validation

Robertson

Wang

2021

Energies

Self Cite

View full text Add to dashboard Cite

A new validation campaign was conducted at the W2 Harold Alfond Ocean Engineering Laboratory at the University of Maine to investigate the hydrodynamic loading on floating offshore wind substructures, with a focus on the low-frequency contributions that tend to drive extreme and fatigue loading in semisubmersible designs. A component-level approach was taken to examine the hydrodynamic loads on individual parts of the semisubmersible in isolation and then in the presence of other members to assess the change in hydrodynamic loading. A variety of wave conditions were investigated, including bichromatic waves, to provide a direct assessment of difference-frequency wave loading. An assessment of the impact of wave uncertainty on the loading was performed, with the goal of enabling validation with this dataset of numerical models with different levels of fidelity. The dataset is openly available for public use and can be downloaded from the U.S. Department of Energy Data Archive and Portal.

show abstract

Effects of turbulent wind and irregular waves on the dynamic characteristics of a floating offshore wind turbine platform

et al. 2023

View full text Add to dashboard Cite

OC6 Phase Ib: Validation of the CFD predictions of difference-frequency wave excitation on a FOWT semisubmersible

Cited by 31 publications

References 53 publications

OC6 Phase Ia: CFD Simulations of the Free-Decay Motion of the DeepCwind Semisubmersible

OC6 Phase Ia: CFD Simulations of the Free-Decay Motion of the DeepCwind Semisubmersible

OC6 Phase Ib: Floating Wind Component Experiment for Difference-Frequency Hydrodynamic Load Validation

Effects of turbulent wind and irregular waves on the dynamic characteristics of a floating offshore wind turbine platform

Contact Info

Product

Resources

About