Evaluation of the Effect of Terrain on Wind Speed Using Analytical Method
S. Olu Adesogan *
Department of Civil Engineering, Federal University Oye-Ekiti, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The causal factor of roof blown-off is wind, most of the roof designers do not have enough information on the wind environment in which they work and as such do not take into consideration the effect of terrain on wind speed uphill. It is therefore reasonable to know the maximum wind speed forecast for any building at a specified locations. A Survey of roof blown-offs in South-western Nigeria comprising of Ekiti, Lagos, Ogun, Ondo, Osun and Oyo States was conducted between 2011 and 2013 to ascertain the influence of the various environmental conditions and roof properties on roof blown-off. This survey resulted in MODEL FORMULATION. Variations of wind speeds with respect to topographical location of the building were investigated in this paper. Relations between this variable was then drawn up using analytical method. In modeling the wind speed along the slope uphill, the general fluid equation and Peronian equations were both employed to show that there is a relationship between wind speed at the valley and wind speed at the crest of a hill. The model was validated using data from four different stations at Ibadan. The t values for the stations are 0.215, 0.533, 0.298, 0.517 respectively indicating that there are no significant difference in the use of the model and the actual wind measurement indicating that the model is good.
Keywords: Modeling, wind speed, valley, hill crest, venturi effect