Influence of Viscosity and Non-linearities in Predicting Motions of a Wind Energy Offshore Platform in Regular Waves
Name
omae_142_6_062003.pdf
Description
Published version
Size
796.53 KB
Format
Unknown
Checksum (MD5)
6f7d03bd305a7781d1476c3e60676b0f
Author(s)
Ferrandis, José del Águila
Bonfiglio, Luca
Rodríguez, Ricardo Zamora
Chryssostomidis, Chryssostomos
Faltinsen, Odd Magnus
Triantafyllou, Michael
Date Issued
May 2020
Journal
Journal of Offshore Mechanics and Arctic Engineering
Publisher
ASME International
Citation
Ferrandis, José del Águila, Bonfiglio, Luca, Rodríguez, Ricardo Zamora, Chryssostomidis, Chryssostomos, Faltinsen, Odd Magnus et al. 2020. "Influence of Viscosity and Non-linearities in Predicting Motions of a Wind Energy Offshore Platform in Regular Waves." Journal of Offshore Mechanics and Arctic Engineering, 142 (6).
Version
Final published version
Abstract
Abstract
Motion predictions of floating bodies in extreme waves represent a challenging problem in naval hydrodynamics. The solution of the seakeeping problem involves the study of complex non-linear wave-body interactions that require large computational costs. For this reason, over the years, many seakeeping models have been formulated in order to predict ship motions using simplified flow theories, usually based on potential flow theories. Neglecting viscous effects in the wave-induced forces might largely underestimate the energy dissipated by the system. This problem is particularly relevant for unconventional floating bodies at resonance. In these operating conditions, the linear assumption is no longer valid, and conventional boundary element methods, based on potential flow, might predict unrealistic large responses if not corrected with empirical viscous damping coefficients. The application considered in this study is an offshore platform to be operated in a wind farm requiring operability even in extreme meteorological conditions. In this paper, we compare heave and pitch response amplitude operators predicted for an offshore platform using three different seakeeping models of increasing complexity, namely, a frequency-domain boundary element method (BEM), a partly nonlinear time domain BEM, and a non-linear viscous model based on the solution of the unsteady Reynolds-averaged Navier–Stokes (URANS) equations. Results are critically compared in terms of accuracy, applicability, and computational costs.
Motion predictions of floating bodies in extreme waves represent a challenging problem in naval hydrodynamics. The solution of the seakeeping problem involves the study of complex non-linear wave-body interactions that require large computational costs. For this reason, over the years, many seakeeping models have been formulated in order to predict ship motions using simplified flow theories, usually based on potential flow theories. Neglecting viscous effects in the wave-induced forces might largely underestimate the energy dissipated by the system. This problem is particularly relevant for unconventional floating bodies at resonance. In these operating conditions, the linear assumption is no longer valid, and conventional boundary element methods, based on potential flow, might predict unrealistic large responses if not corrected with empirical viscous damping coefficients. The application considered in this study is an offshore platform to be operated in a wind farm requiring operability even in extreme meteorological conditions. In this paper, we compare heave and pitch response amplitude operators predicted for an offshore platform using three different seakeeping models of increasing complexity, namely, a frequency-domain boundary element method (BEM), a partly nonlinear time domain BEM, and a non-linear viscous model based on the solution of the unsteady Reynolds-averaged Navier–Stokes (URANS) equations. Results are critically compared in terms of accuracy, applicability, and computational costs.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Sea Grant College Program
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1115/1.4047128
