LES Study on flow mechanism of large peak suctions near corners of a three-dimensional square cylinder by change of wind direction

Abstract

The objective of this paper is to clarify the pressure characteristics of a square cylinder when wind direction is changed by using LES. Based on the computed results,the large peak suctions are recognized near the corners of a square cylinder in some cases. The flow characteristics associated with the large peak suction are investigated.In the case of the gradually change of the wind direction, the flow separation and reattachment near the frontal corners change to formation of separated shear layer in the wake region as observed in the flow patterns around a square cylinder. On the other hand, when wind direction largely changes, the large peak suctions are caused by the difference of the timing between flow characteristics near the square cylinder and approaching flow.