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The aerodynamic loadings of a 5:1 rectangular cylinder in one-dimensional sinusoidal flows are experimentally tested in a multiple-fan active control wind tunnel. A series of single-frequency streamwise sinusoidal flows, which are fully coherent in the spanwise direction, are generated by changing the frequency and amplitude. Spectral analysis indicates that the total drag, lift forces, and pitching moment contain the inflow-induced components as well as those induced by vortex shedding. To identify the two-dimensional aerodynamic admittances (2D AAF), the vortex-induced components are separated from the inflow-induced components by using the POD method. Subsequently, the 2D AAFs of the drag, lift forces and pitching moment are identified and compared with the empirical or theoretical models. Results show that the inflow amplitude has a limited influence on the 2D AAFs, while the angle of attack (AoA) can cause significant changes in them. At a zero AoA, the 2D drag AAF is in alignment with the Davenport function and the 2D lift AAF is close to Horlock's AAF at low frequencies. Meanwhile, the 2D drag AAF is less influenced by the AoA than the lift and moment AAFs. The relationships between the inflow-induced and vortex shedding-induced components of the total forces are also discussed. The two-dimensional drag, lift, and moment aerodynamic admittances of a 5:1 rectangular cylinder are experimentally identified in one-dimensional streamwise sinusoidal flows. The vortex-induced components of total forces are separated from the inflow-induced ones and the latter is utilized to identify the two-dimensional aerodynamic admittances. Results show that the inflow amplitude has limited influences on the 2D AAF, while the angle of attack (AoA) causes significant changes in them. At zero AoA, the 2D drag AAF is in agreement with Davenport's AAF, and the 2D lift AAF is close to the Horlock's AAF at low frequencies (ω ​≤ ​5). On the other hand, the 2D lift and moment AAF at zero AoA are much higher than those at non-zero AoAs, indicating more unsteady features. The present method can be applied in the buffeting analyses of large-span line-like structures. Image 1 • Aerodynamic forces on a 5:1 rectangular cylinder are measured in sinusoidal flows. • Inflow-induced and vortex-induced components of the total forces are separated. • Two-dimensional drag, lift, and moment aerodynamic admittance (AAF) are identified. • Effects of inflow amplitude and attack angle on the AAFs are analyzed. [ABSTRACT FROM AUTHOR]

In this paper, the two-dimensional lift, drag and pitching moment aerodynamic admittances of three typical bridge deck sections, including a streamlined box section, an edge section and a truss section are identified by wind tunnel tests using a statistical identification approach and high-frequency dynamic balance measurement technique. An empirical formula for determining the two-dimensional aerodynamic admittance is proposed and compared with the commonly used Sears function and Davenport function. The results show that the two-dimensional lift and moment aerodynamic admittances for the three types of bridge decks are larger than Sears' function in the concerned wavenumber range of the buffeting analysis. This indicates that the Sears function may underestimate the vertical and torsional buffeting response of prototype long-span bridges. The two-dimensional drag aerodynamic admittance of the truss section corresponds strongly with Davenport's function, which verifies the reasonableness of Davenport's function that was originally developed for the two-dimensional drag aerodynamic admittance of open lattice structures. Furthermore, it was found that the two-dimensional aerodynamic admittance is insensitive to the mean wind velocity. The effect of wind attack angle on the two-dimensional aerodynamic admittance of bridge decks cannot be neglected. • The 2D AAFs of a streamlined box section, an edge section and a truss section are identified. • The empirical formulas of the 2D lift, drag and pitching moment AAFs are given. • The 2D AAFs are compared with the commonly used Sears function and Davenport function. • The effects of the mean wind velocity and angle of attack on the 2D AAFs are analyzed. [ABSTRACT FROM AUTHOR]