Modification of pedestrian wind comfort in the Silvertop Tower passages by an automatic control system

The Silvertop Towers project is a comprehensive redevelopment project of three high-rise residential buildings in the city of Antwerp (Flanders, Belgium). As part of this project, pedestrian passages will be constructed through each of the towers to improve the accessibility and to increase social control on the site. Experience, wind tunnel modeling and numerical modeling have indicated that wind conditions in passages are often unfavorable. This paper presents the assessment of wind climate and especially the study that has been performed to modify the wind climate in the passages of the Silvertop Towers. The assessment of wind climate is conducted with the aid of numerical modeling with Computational Fluid Dynamics. The wind climate is assessed to be highly unacceptable. Remedial action is imperative. Various traditional remedial measures to improve the wind climate are contemplated. These solutions either provide an insufficient improvement of wind climate or conflict with the envisaged architectural design. Therefore a rather unconventional solution has been selected. We have designed and analyzed an automatic control system to modify the wind climate in the passages. The actuators of the system are sliding doors that are mounted at both ends of the passage. The opening and closing of the doors is controlled by a decision algorithm based on local wind measurements. At least one of the doors will be closed when the control system senses that the threshold wind speed in the passage is exceeded. The control system will ensure an adequate wind climate without conflicting with the original architectural design. The passages are estimated to be opened for about 50-70% of the time. Estimates for the fraction of time that door control is imperfect (doors are closed instead of open and vice versa) are also given. (C) 2004 Elsevier Ltd. All rights reserved.