Fluctuating wind velocity spectra of moving vehicle under horizontal crosswind

Abstract

In order to study the wind speed spectrum of moving vehicles under horizontal crosswind with different vehicle speed/wind speed ratios, the Taylor “frozen” turbulent flow assumption is applied to derive the auto-correlation coefficient function of the moving point. The self-power spectral function of the moving point is solved by the Fourier transform analysis. Based on the existing expression forms of the fluctuating wind speed spectra, the analytical expression of the self-power spectral function of the moving point of which wind speed is perpendicular to the vehicle speed is derived directly by the integral transformation. Research shows: due to the movement of vehicles, the longitudinal fluctuating wind speed spectrum of moving point is shifted to high frequency. With the increase of vehicle speed, the amplitude decreases and then increases gradually. Meanwhile, the amplitude of lateral fluctuating wind speed spectrum of moving point decreases firstly with the increase of vehicle speed, and then increases gradually.