Numerical analysis of fluid flow dynamics around two side-by-side square cylinders in the presence and absence of splitter plate

This study is concerned with the analysis of the characteristics of flow around two side-by-side square cylinders in presence and absence of splitter plate. The gap spacing (g) between both cylinders as well as between splitter plate and cylinders is varied from 0 to 4 and height of splitter plate is varied from 0.2 to 0.8 with fixed Reynolds number (Re) = 150. Lattice Boltzmann method is used in this analysis to numerically compute the fluid flow characteristics. Two different arrangements are considered in this study; arrangement-I: two side-by-side square cylinders without a splitter plate, arrangement-II: splitter plate placed at the rear side of two side-by-side square cylinders. Based on different characteristics, the flow structure is divided into seven different flow patterns for both arrangements. The mean drag coefficient (Cdmean), Strouhal number (St), root-mean-square values of drag and lift coefficients (Cdrms and Clrms) of two side-by-side square cylinders with and without splitter plate are compared. It is observed that Cdmean, Cdrms and Clrms of both cylinders reduced significantly at smaller splitter heights as compared to higher splitter heights at small g while at intermediate g these values reduced at all values of splitter heights. An interesting fact is observed that the placement of splitter plate at downstream of two side-by-side square cylinders does not always minimize the magnitude of fluid forces instead for some splitter heights the magnitude of fluid forces increases instead of decreasing.