Abstract

Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer (ABL) by using roughness devices such as vortex generators, floor roughness, barrier walls, and slots in the extended test-section floor in the contraction cone. Each passive device impacts wind properties in a certain way. In this study, influence of various passive devices on wind properties has been investigated. Experiments using eighteen different configurations of the passive devices have been carried out to simulate urban, sub-urban, and rural climate conditions in a boundary-layer wind tunnel. The effect of each configuration on the wind characteristics is presented. It was found that higher barrier height and more number of roughness elements on the floor, generated higher turbulence and therefore higher model scale factors were obtained. However, increased slot width in the extended test-section floor in the contraction cone of the wind tunnel seemed to have a little effect on wind characteristics.

Key words: Atmospheric boundary layer, wind tunnel, wind properties, roughness elements, turbulence.