WIND-TUNNEL TECHNIQUES FOR ASSESSMENT OF PEDESTRIAN-LEVEL WINDS

Wind conditions around high-rise buildings in cities may create seriou s environmental problems at the pedestrian level. In spite of the prog ress of computational techniques in wind engineering, wind-tunnel expe riments are still considered to be the most reliable approach for the evaluation of pedestrian-level winds. A number of techniques have been developed for assessing the mean and turbulent characteristics of the wind regime around buildings near the ground. These techniques can be grouped into two categories: point methods and area methods. This pap er reviews the experimental methods and discusses their advantages and limitations with respect to the requirements of pedestrian-level wind studies. In addition to conventional techniques such as thermal anemo metry, pressure sensor, flow visualization and erosion, some newly dev eloped methodologies such as laser-Doppler anemometry, particle-image velocimetry, and infrared thermography are described. The selection of the most appropriate experimental methodology for the best assessment of pedestrian-level wind conditions is discussed in terms of spatial coverage and accuracy.