Abstract
Lateral space spectrum is obtained from a simple model based on the experimental results in high wind conditions. The logarithmic space spectrum has a peak at wave number of about 0.025m-1, which corresponds to 250m in terms of wave length, at the height of 41.5m above the ground. This wave number is approximately 3.2 times larger than peak wave number of longitudinal space spectrum.
The effects of averaging time and sampling duration on lateral space correlation and spectrum are estimated from the above model. Sampling durations more than 300 seconds have effects of little significance, but averaging time has appreciable effects. Peak wave number of space spectrum varies a little with increasing averaging time when it becomes more than one second.
Lateral space spectrum obtained from the above model is expressed by a simple algebraic expression. Applying this expression to the modified Davenport's theory, gust factors of fluctuations of wind velocities averaged over lateral distance are obtained. Normarized cospectrum of vertical velocities between two points with lateral separations is obtained. Using this result, lateral space spectrum of vertical velocity is obtained with the similar method to that of longitudinal velocity though this is very rough estimate due to insufficient number of data. The peak wave number of the logarithmic spectrum is nearly equal to 0.105m-1.
