Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
NUMERICAL STUDIES OF FLOW AROUND FOUR CYLINDERS IN SQUARE ARRANGEMENT
Submission Author:
Paulo Vitor Reis Guilherme , SC
Co-Authors:
Paulo Vitor Reis Guilherme, Aline Leal de Lima Gontarski, André Fujarra
Presenter: Paulo Vitor Reis Guilherme
doi://10.26678/ABCM.COBEM2021.COB2021-1954
Abstract
Bodies submerged in water are rarely isolated. Instead of, the wake becoming from other bodies can strongly influence the response behavior, specially talking about amplitude of forces and movements. Offshore platforms as semisubmersibles have their four columns in square array and the study of motion in this case can be related to the platform movement induced by the flow, phenomenon known as flow-induced motion (FIM). The flow around four equal cylinders were analysed on this work, evaluating different relative distances between cylinders (T/D = 2, 3, 4, 5, 6) in CFD calculations. The study is treated in a way to present preliminary and reliable results for an array design, the flow is two-dimensional and at low Reynolds number (Re = 100), this approach proves to be advantageous in the selection of results and comparison with more elaborate simulations and experiments. Numerical calculations were carried out evaluating different number of cells and time steps in order to conduct uncertainty analysis, so the results are presented with their respective uncertainty intervals. The columns were evaluated in the stationary situation, i.e. no degree of freedom, where force coefficients and frequencies were analysed. It was noticed that the numerical results of this research presented good agreements with other numerical ones found in the literature, and symmetry results were found. The wake between the cylinders for S ≥ 4 showed strong influence in the downstream response and some similarities related to the wake were found in comparison with two cylinders in tandem arrangement cases.
Keywords
square array, four cylinders, CFD, FIM, VIM
