Turbulence intensity effect on the bluff bodies aerodynamic behavior

Slender high rise structures are exposed to aerodynamic problems connected to the windstructure interaction, for example vortex shedding or dynamic instability (e.g. galloping). Generally the design of these structures requires the aid of wind tunnel tests on scaled models. The paper investigates the aerodynamic behavior of a bluff body and the shape is adopted for section of the tower of a cable-stayed bridge (Fossati et al. 2011). The problem is investigated by wind tunnel tests using a rigid sectional model with particular attention on the effects related to the turbulence intensity of the incoming flow. The present paper shows the results obtained in terms of aerodynamic forces and pressure distributions for two level of turbulence, Iu=0.2 % and Iu=2 %. Vortex shedding phenomenon in these two conditions will be also discussed.