Wind Disturbance by a Vertical Cylinder in the Atmospheric Surface Layer

Abstract

The velocity distribution in the neighborhood of a cylindrical obstacle was measured over the frozen surface of Lake Mendota, Madison, Wis. Non-dimensional isotach patterns were constructed depicting the velocity distribution at two levels within the atmospheric surface layer. Differences in the vertical shear between the two levels is seen to affect the nature of the patterns. Wind speed reductions of 6% are noted upwind of the cylinder and in excess of 40% downwind. The upwind pattern is fairly well represented by the potential solution; the more complex downwind pattern is asymmetrical. Large vertical components of the velocity were computed.