Comparison of Nonlinear Wave-Loading Models on Rigid Cylinders in Regular Waves

Bibliographic Details
Title: Comparison of Nonlinear Wave-Loading Models on Rigid Cylinders in Regular Waves
Authors: Agota MockutÄ—, Enzo Marino, Claudio Lugni, Claudio Borri
Source: Energies, Vol 12, Iss 21, p 4022 (2019)
Publisher Information: MDPI AG, 2019.
Publication Year: 2019
Collection: LCC:Technology
Subject Terms: offshore wind turbines, monopile, ringing, secondary load cycle, nonlinear waves, hydrodynamic loading models, truncated surface-piercing cylinder, regular waves, Technology
More Details: Monopiles able to support very large offshore wind turbines are slender structures susceptible to nonlinear resonant phenomena. With the aim to better understand and model the wave-loading on these structures in very steep waves where ringing occurs and the numerical wave-loading models tend to lose validity, this study investigates the distinct influences of nonlinearities in the wave kinematics and in the hydrodynamic loading models. Six wave kinematics from linear to fully nonlinear are modelled in combination with four hydrodynamic loading models from three theories, assessing the effects of both types of nonlinearities and the wave conditions where each type has stronger influence. The main findings include that the nonlinearities in the wave kinematics have stronger influence in the intermediate water depth, while the choice of the hydrodynamic loading model has larger influence in deep water. Moreover, finite-depth FNV theory captures the loading in the widest range of wave and cylinder conditions. The areas of worst prediction by the numerical models were found to be the largest steepness and wave numbers for second harmonic, as well as the vicinity of the wave-breaking limit, especially for the third harmonic. The main cause is the non-monotonic growth of the experimental loading with increasing steepness due to flow separation, which leads to increasing numerical overpredictions since the numerical wave-loading models increase monotonically.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1996-1073
Relation: https://www.mdpi.com/1996-1073/12/21/4022; https://doaj.org/toc/1996-1073
DOI: 10.3390/en12214022
Access URL: https://doaj.org/article/aa4e4679b11c4fa696231064667fe7c9
Accession Number: edsdoj.4e4679b11c4fa696231064667fe7c9
Database: Directory of Open Access Journals
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More Details
ISSN:19961073
DOI:10.3390/en12214022
Published in:Energies
Language:English