Airflow, building height diference and wind tunnel test

This paper presents wind tunnel simulation as a tool to verify how changes to height and positioning of buildings close to the sea coast affect airflow in the area. The simulations were made for an area of the city of Santos, Pompéia, between Channels 1 and 2, on the southern shore of São Paulo State, Brasil. The area and blocks were chosen due to the the existence of tall buildings (in comparison with others) in the area, as well as its current urban configuration. The configuration in this area encompasses tall buildings (between 15 and 17 floors) on the sea coast, which form a wall for the areas beyond them, and lower-height buildings in an intermediate area (central square, from 6 to 8 floors), with 2 to 3-floor buildings on the limit-area (avenue / railway tracks). The wind-tunnel simulations were conducted at the LNEC (Laboratório Nacional de Engenharia Civil), in Portugal, with the erosion-figure technique, to verify the influence of new buildings in the natural ventilation conditions at the user / pedestrian level. Changes were proposed to certain points, based on the existing ocupation, basically on the second block behind the sea-coast wall, to verify changes in wind speed and direction. As the area is seeing the appearace of buildings with 26 floors, it was decided to insert this height in the block posterior to the sea-coast. The simulations enabled verificatio of what happens in the existing situation and with the proposed changes and were made with seven configurations. Buildings were placed according to the developing occupation. These simulations are valid for this type of change. New simulations have to be conducted for specific proposed changes. The wind-tunnel simulations showed and confirmed that changes to the height and positioning of buildings changed wind pattern in the area under study.