Bluff-body aerodynamics: Research challenges from wind engineering

The evaluation of wind-induced loads poses challenging problems of bluff-body aerodynamics because, from an aerodynamic point of view, almost all civil structures are bluff bodies. In order to devise physically sound design procedures, considerable research is still necessary as regards many important topics, a few of which are briefly reviewed in the present paper by mainly focusing on recent developments. Vortex shedding response and galloping are first considered, as well as their possible interaction, which is a complex and open issue. The interference between bluff bodies and its ensuing effects on the aerodynamic loads and on the possible aeroelastic phenomena are then considered, pointing out the still unsatisfactory level of the relevant present information. Finally, the problem of the prediction of the loads acting on bodies subjected to accelerating flows, like those that may often occur in thunderstorms, is tackled. In particular, the present available procedures to evaluate acceleration-induced forces are critically described, together with a discussion on their potential importance in wind engineering.