Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Analysis and validation of wave absorption strategies for CFD simulation using OpenFOAM
Submission Author:
Samuel Gonçalves , SC
Co-Authors:
Samuel Gonçalves, Ernane Silva, Pedro Cardozo de Mello, Thiago Pontin Tancredi, Filipe Dutra da Silva, André Fujarra
Presenter: Samuel Gonçalves
doi://10.26678/ABCM.COBEM2023.COB2023-1169
Abstract
The fatigue evaluation of floating platform moorings has been increasingly necessary due to the early failure of several installations around the world in the last years. The phenomena responsible for this problem are categorized as fluid-structural interaction and one of them is wave-induced motion. Motions in platforms can raise the insecurity of its operation, but even in situations where the platform operations aren’t affected by wave action they put in proof the life in fatigue of the mooring systems, making them vulnerable to failures earlier than expected as also needing more periodic maintenance and, consequently, increasing the cost of the whole platform operation. In final design phases, the performance of the combination of these parameters can be evaluated through Computational Fluid Dynamics (CFD) simulations of the wave-induced platform motions for different frequencies, where the motion amplitudes can be evaluated based on the designed moorings and the Response Amplitude Operator (RAO) curve can be obtained, which describes the platform’s seakeeping based on the main dimensions and mass. Previous studies by the authors utilizing the open-source CFD software OpenFOAM involving floating body dynamics with simple geometries served as an initial approach to the study of wave energy converters, but also contributes to the study of floating platforms. The wave generation model utilized in the previous study, despite low discrepancies in relation to the experimental data, was considered validated due to its low computational cost and the fact that the numerical versus experimental data comparison of the reference study also presented discrepancies in the same magnitude order. In order to advance the study within the scope of improving the correlation between numerically simulated and experimentally generated waves, this paper describes the implementation and evaluation of different strategies for passive wave absorption which include porous regions and physical beaches together with the native active absorption of the olaFlow extension, also responsible for the wave generation, in addition to self-authored experimental results to validate the numerical model. The solution that presented the best results for a selected wave in relation to its input parameters was the beach-shaped porous region. With the optimized absorption case, three waves were simulated which had their values compared with the experimental data, showing an excellent correlation.
Keywords
Wave Absorption, CFD simulations, OpenFOAM, Floating platforms, experimental validation
