EXPERIMENTAL STUDY OF ROUGHNESS EFFECTS ON TURBULENT BOUNDARY LAYER FLOW OVER A TWO-DIMENSIONAL HILL | ||||
| JES. Journal of Engineering Sciences | ||||
| Article 10, Volume 34, No 6, November and December 2006, Page 1831-1841 PDF (859.29 K) | ||||
| Document Type: Research Paper | ||||
| DOI: 10.21608/jesaun.2006.111355 | ||||
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| Author | ||||
Mohamed F. Yassin 
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| Mining and Metallurgical Engineering Department, Faculty of Engineering, Assiut University, Assiut-71516, Egypt | ||||
| Abstract | ||||
| Wind tunnel experiments were carried out to study the effects of surface roughness on a turbulent boundary layer over a twodimensional hill under neutral conditions by using a hot wire Constant Temperature Anemometer (CTA) system with a split-fibre probe. Rough surface conditions were modeled by placing two types of windbreak fence on the hill surface. Its porosities are 0% and 50%. Measurements analysis includes mean velocity, turbulent velocity, Reynolds stress, turbulent energy and eddy viscosity profiles over the hill surface and in the wake region. The results obtained indicate the following: a) the mean velocity profiles for the types of windbreak fence slightly changes with the different fence arrangements, b) the turbulent velocity shows an almost uniform distribution across the windward ascent slope, c) the turbulence velocity becomes higher at the upper wake region behind the hill, d) the porous fences work as strong windbreaks and weaken the wind velocity near the hill surface. This study can help to improve the database for validating the CFD method for predicting wind over a local terrain | ||||
| Keywords | ||||
| Boundary layer; Hill; Mean flow; Roughness; Split fibre measurements | ||||
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