Abstract:
his study was carried out to determine the influences of different windbreak lengths
on the wind speed of the downwind side of windbreaks. The windbreaks and the wind
speed sensors were constructed from locally available materials. The lengths of the
windbreak were varied by gradually adding panels in the frames initially prepared
for this purpose. Seven wind speed sensors were arranged at equal separation along
a quadrant of a circle on the downwind side of a windbreak. Measurements were
conducted for short durations only when wind speed was sufficient enough to rotate
the sensors. The results of measurements showed that wind speeds decayed
exponentially on the downwind side of the windbreak only up to a certain distance
which in this study was found to be 6 m. After this distance wind speed recovery took
place and the exponential decay was good only up to this distance. Windbreaks of
small length (< 3.6 m) did not perform well in clearly demarking the protection zone.
The length of windbreak 3.6m, 4.8m, 6m and 7.2m are effective because they
managed to reduce the wind speed up to 6m completely. The average managing
percentage was 82%. In this test we found the influence of windbreak on the
leeward to be about four times the height of the windbreak. We therefore emphasize
the importance of calibration of the wind sensor if the method is to be used for future
work.
