Bluff body aerodynamics in wind engineering

Most of the man made structures are bluff bodies. Therefore, the subject of this conference is central to the subject of wind engineering. One of the most obvious features of the flow around bluff bodies is the formation of strong large vortices in their wakes. These have a large impact on the wind loading of tall buildings and bridges, particularly the loading in the across-wind direction. Not only is the design for structural integrity affected but also the design for serviceability, since the motions induced by vortex shedding can easily reach objectionable levels from the point of view of human comfort. However, measures can be taken to reduce the effects of vortex shedding, including shape changes and supplemental damping devices. Wind turbulence is also a parameter that affects vortex shedding strongly and this can be sensitive to the terrain around the structure. Another feature of bluff body flows is that some of them are Reynolds number sensitive. The recent research on the oscillations of inclined cables on cable-stayed bridges reinforces the need always to be cognizant of the potential effects of Reynolds number and its interplay with turbulence and surface roughness.