Research On Buoyancy-driven Ventilation Assisted By Wind In High-rise Residential Building With Atrium

Atrium is the courtyard space inside high-rise residential building. One feature of the atriums is to introduce the natural environment to the building's internal area, as to improve the micro-climate of the building and enhance the indoor air quality; the other is to take full advantage of the atriums'"chimney effect" to enhance natural ventilation, as to remove moisture and other air pollutants with the lowest possible energy consumption. However, high-rise residential buildings with atriums have complex structure, and there are many factors for its ventilation, traditional calculation methods for simple buildings are no longer applicable to such buildings.Firstly, the background of this research work, the research significance and the research status were described. According to the basic theory of natural ventilation, the ventilation mathematical model for high-rise buildings with an atrium were set up, which were induced by single wind force or thermal buoyancy, and the ventilation under the combined effect of wind force and thermal buoyancy were analyzed. Then a 10-storied residential building with an atrium was designed, and the reasonable turbulence model and numerical solution method was established. The model experiment was also conducted in a wind tunnel to validate the reliability and validity of the numerical method. At last, the ventilation characteristics of the building were simulated, which were affected by the ventilation force (outdoor wind speed, indoor heat generation, wind direction), the building shape coefficient, the stair and the size of top orifice in atrium.The results show that under the combined effect of wind force and thermal buoyancy, the ventilation characteristics of the high-rise residential building will change as any one of the ventilation conditions change. Different ventilation conditions cause different ventilation characteristics of the building, the change of the conditions often lead some of the rooms'ventilation enhanced while others were weakened. At the same condition, the ventilation effect of different rooms and different altitude of the atrium is also different, because of at different position the wind pressure coefficient and the thermal buoyancy force are different. In order to enhance the natural ventilation of high-rise residential building, we should take full advantage of the atriums'"chimney effect", to keep the building under the reinforcing pattern of wind force and thermal buoyancy, and avoid the pattern of weakening each other.