Magnitudes and Horizontal Correlations of Vertical Velocities in High Winds

Abstract

This paper deals with turbulent properties of vertical velocities and wind inclinations at height of 40m in strong winds. In the wind of sea trajectory, the intensity of turbulence was mostly in the range from 0.03-0.04. The ratio of vertical velocity to longitudinal one, that of vertical velocity to friction velocity, and non-dimensional frequency _??_m at which logarithmic power spectrum had a maximum were in good agreement with those by other investigators. The lateral correlation was small compared with that of longitudinal velocities. It vanished almost at the separation of 35m. When the square root of coherence was ex-pressed by an exponential function, the decay parameter scattered in a wide range but it was estimated from 14-16 on the average. The effect of averaging on peak values and scales of wind inclinations was discussed as engineering application. With increase of averaging time, peak values decreased and lateral scales increased, but the rate of increase was small compared with that of decrease of the peak values.