Wind Turbulence Behavior and Study of Tower Distortion and Scatter Factors

The performance of wind speed sensors installed at different heights on a 40-meter mast was evaluated during 3 months between July 01, 2006 and April 01, 2009. This evaluation involved estimating the tower distortion factor (TDF) and the scatter factor, and studying the correlation between the co-located wind speed sensors. A total of 23,730 hourly mean wind speed records were used to evaluate each sensor. The overall values of the tower distortion of the wind speed measured by sensors installed at 40 and 30m were found to be 0.025 and 0.021 without tower shading, and 0.047 and 0.035 with tower shading. As indicated by the slightly decreasing TDF values the wind speed measured by the sensors is not distorted with time. Tower shading effect for the wind speed sensor WS5 at 40 meters is pronounced (>1) when wind direction range from 169° to 195°, while that for the wind speed sensors at 30 meters and WS6 at 40 meters, it is less than one when the wind direction is in the 240° to 270° range. The wind speed sensors at 30meters displayed similar behavior and the scatter factor for wind speed sensors at 40meters is higher than that for those at 30meters.Copyright © 2014 by ASME