Horizontal Space Correlations of Velocity Fluctuations during Strong Winds

Abstract

The present paper deals with horizontal space correlations and lateral scales of fluctuating wind velocities observed during strong winds for providing the knowledge of design wind velocity of a long suspension bridge. Five anemometers at height of 40m are located in a line of 190m along the coastline. Horizontal space correlation decreases nearly exponentially with increasing separation, but does not tend to zero within the maximum separation in most of observed cases, Integral scales of turbulence are about 60m in a lateral direction and becomes 2.54 times larger in a longitudinal direction. Turbulent eddies appear to be elongated in the direction of the wind. Lateral scales related to narrow frequency ranges are approximately represented by a linear function of inverse wave numbers in the range not exceeding about 500m. The convection velocity of the eddies is discussed in observed cases that wind directions are not perpendicular to the anemometer line.