Numerical investigation of vortex suppression regions for three staggered circular cylinders

The flow patterns and vortex suppression regions for three circular cylinders with two different staggered arrangements were numerically investigated by the immersed boundary method based lattice Boltzmann method. The first arrangement is that one primary cylinder was placed in front of two assistant cylinders, and the second arrangement is that one primary cylinder was arranged in the wake of two assistant cylinders. The calculations were carried out at fixed spacing ratios with varied Reynolds numbers (100 <= Re <= 200). The flow visualization experiments based on the laser-induced fluorescence technique were also conducted to verify the reliability of simulation results. It was found that the arrangement has a significant influence on the wake structures, force fluctuations and vortex shedding suppression. In the first arrangement, the vortex shedding behind the leading cylinder is suppressed by two assistant cylinders at 100 <= Re <= 200. In the second arrangement, however, the vortex shedding of the trailing cylinder is suppressed by two assistant cylinders at 103 <= Re <= 175. The current results are helpful for designing multiple piers in the practical applications. (C) 2015 Elsevier Masson SAS. All rights reserved.