Vorticity contours shown in Fig. 9(a1), (a2) and (a3) reveal the intensity of the secondary flows induced by the vortex shedding. The vortices shed by the spacers dissipate as they Tariquidar are convected away from the cylinders. Fig. 9a illustrates that the flow induced by the vortex shedding in the wake region of spacers is strongly influenced by the proximity of the walls. The similar flow structures are reported by Singha and Sinhamahapatra  and Sahin and Owens  in the channel containing spacers with the same blockage ratio at the similar flow rates.