CFD Simulation Of Wind Environment And Natural Ventilation In Residential Quarters

The use of air conditioning is the main source of building energy, causing a huge pressure on the power supply in summer, which made passive building design become to the focus attention of architecture industry. With the obviously advantage of low cost, easily implied and operated, ventilation by external window was determined to be an energy-saving technology in passive buildings. With the aid of computational fluid dynamics(CFD is to the short of Computational Fluid Dynamics) software PHOENICS, using finite volume method, k-? turbulence model, SIMPLE algorithm, and second order upwind format, this paper simulated and analyzed the parameters effected about residential building natural ventilation based on the meteorological data of Chifeng. First of all, to analysis of the influence of architectural layout of indoor natural ventilation, the wind environment of residential building was simulated, calculating parameters were the surface wind pressure of rear building and air change rate, then in several schemes for the design assumptions worked out the most reasonable construction plan. And then, the impact of the external windows parameters were investigated including the ratio of the area of the external window and the floor area of the room, the relative location of the outside windows and the height of the window sill, the calculating parameters were the mean age of air and air change rate. Finally, we could gain the right design strategy of building layout and window parameter with natural ventilation in room, so that the residential building would meet the requirements of green ventilation.The results showed that when the width of the first row of buildings less than the rear building width and spacing between the buildings at 20 m, the windward side pressure of rear building were positive, the ventilation efficiency is better than other building layout. In winter, Commercial buildings placed on the windward side of the upstream section reducing the living building air permeability; when the summer wind flow came straight to the building orientation, to make full use of natural ventilation and reduce air conditioning load; With summer windward direction from front to back, construction arrangement lined sequentially from low to high, indoor architectural would get the most favorable room mean age of air and the ventilation frequency, then the right design strategy of building was layout. When the relative distances of the convective outer window is zero, the larger the ratios of the area of the external window and the floor area of the room change, the greater the air change rates obtain and the smaller the mean ages of air stay. When the ratio of the area of the external window and the floor area of the room is in same, the distance of the relative position of the convective outer window is larger, the change of the air change rates remain constant, but the mean ages of air ease with a straight line. The change of sill height had little effect on the air change rate and the mean age of air. This paper calculated and analyzed the construction of the external flow field, the wind pressure on the building surface and the number of indoor ventilation, mean age of air which has a certain guiding significance in designing strategy of building and indoor window parameters.