On the response of a bridge deck to turbulent wind: a new approach

In spite of getting the aerodynamic parameters to be used in numerical simulations of a bridge deck response to turbulent wind, wind tunnel tests play a crucial role. The aerodynamic admittance function is one of the most difficult to be measured since controlling the incoming flow turbulence spectrum is a primary need and because admittance is a function of the mean wind-to-deck relative angle changing in time and space. In the present paper, an active turbulence generator is proposed, capable to generate a controlled and easy-to-change 2D oscillating flow, making it possible to measure a complex admittance function instead of the commonly adopted real function. The main features of the flow given by the generator are analysed and evaluated and the preliminary results are discussed.