Influence of dimensions of square cylinders arranged at the vertices of an equilateral triangle on the behavior of the
wake flow is analyzed in the present study. Numerical computations based on the finite volume method (FVM) and a
full multigrid technique (FMG) is applied to resolve the governing equations. Three main arrangements are adopted
in terms of the cylinders positions in an equilateral triangle and effects of various parameters, namely; the cylinder dimensions and the Reynolds number (Re) on the flow pattern are analyzed. The flow characteristics are analyzed for the three-cylinder combinations in terms of iso-vortices for different flow regimes, namely, the crawling, steady, and unsteady regimes. Of great interest is the analysis of the combined effect of the Reynolds number and the adopted
arrangements on the evolutions profiles of the lift (<i>CL</i>) and drag (<i>CD</i>) coefficients. Among the numerical outcomes, it is revealed that according to each configuration and cylinder dimension, the <i>CL</i> and <i>CD</i> values vary differently and dramatically when the Reynolds value is monotonously varied in special ranges.