Processes of buffeting and vortex forces in turbulent wind

Abstract

Abstract An aerodynamic admittance model for the simulation of vector processes of buffeting forces on slender, horizontal and vertical bodies is presented, which is thought to be used for the time domain calculation of flexible structures. The equations for wind buffeting are statistically linearized and make use of spatially averaged turbulence. A numerically generated, continuous field of non-homogeneous turbulence is used as the stochastic input. Typical stochastic properties, such as the turbulence-induced smoothing of mean force coefficients, the non-stationary energy decay of buffeting action in the inertial subrange of turbulence, and the cross-correlations due to the non-homogeneity of the wind, are retained. The action of signature turbulence is limited to the consideration of regular eddy-shedding, for which the typical broad-banded response of vortex excitation is generated by a pseudo-harmonical force model with a stochastic frequency-modulation. The force models have mathematically equivalent representations in time and frequency domains. All elements of the force model are verified comparing simulated and measured force responses of slender and line-like bodies.