The purpose of this paper is to investigate the characteristics of local severe suction on side face of a three-dimensional square cylinder by LES. According to the previous researches, the occurrence of local suctions at the angle of the attack α=0o, and glancing angle are focused on. First, the computed results for distribution of the pressure coefficients are validated through comparison with the experimental data. Next, based on computed results, the relationships between the flow characteristics and the pressure characteristics at the angle of the attack α=0o, and 15o are examined. Finally, we discuss the flow mechanism which leads to unsteady local severe suction on the side face of the square cylinder.
