Numerical investigations of the flow around four non-aligned circular cylinders

Abstract

This works aims at numerically investigating the flow around a group of four non-aligned cylinders, for two different angles of incidence, β = 0° and 180° at Reynolds number (Re) equal to 200. The influence of the proximity between the cylinders is investigated by means of the numerical analysis based on Computational Fluid Dynamics (CFD), using a finite volume method with two-dimensional unstructured meshes. The distance between cylinders and the angle of incidence has a great influence on the flow behavior, which is reflected on the analysis of the force coefficients and the Strouhal number. At β = 0°, it is observed the presence of two regimes in the time series of the lift coefficient, which lifespan of the first regime is reduced with increase of the spacing ratio. Also, different drag coefficients were seen at spacing ratio equals to 3.5 D for the rear cylinders. Regarding to the results with β = 180°, they showed multiple peaks on the lift coefficient amplitude spectrum for the rear cylinders. This work contributes to enhance the understanding of the flow around multiple cylinders, mainly regarding non-traditional configurations such as tandem and side-by-side arrangements.