Wind turbulence effects for 2-D rectangular prisms at high Reynolds number

The general assumption that the aerodynamics of bluff body with sharp edges is independent of Reynolds number has been questioned in recent years. Studies in full-scale on existing structures have indicated a certain degree of sensitivity of these shapes to Reynolds number, highlighting the need to establish an aerodynamic definition for bluff body with sharp edges. In this study, the effect of turbulence at high Reynolds number regime around 10(6) for nine different bluff bodies with sharp edges has been investigated and compared to the effects of turbulence for the same shapes at low Reynolds number. It was concluded that for the Reynolds number regime covered in this study, the turbulence intensity tend to decrease the potential of aerodynamic instability for the bluff bodies with sharp edges studied. However, prisms with square edges do not need the same level of turbulence at high and low Reynolds number to become aerodynamically stable; stability defined as a positive rate of change of lift coefficient with angle of wind incidence. It was observed that for a Reynolds number of 10(6), the amount of turbulence needed to provide a positive slope of the lift coefficient was less important than at 10(4). On the other hand, edge treatment like chamfer, reduces the turbulence intensity required for a given bluff body dimension compare to a square edge configuration to obtain aerodynamically stable characteristics and to avoid potential galloping motion.