Turbulence characteristics of wind over a hill with a rough surface

The turbulence characteristics of a boundary layer flow over a two-dimensional hill with a rough surface are investigated through experiments conducted in a wind tunnel under neutral conditions by using a hot wire constant temperature anemometer system with a split-fiber probe. Two types of windbreak fence are used to set on the hill surface. Its porosities φ 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 change 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.