2004 Volume 29 Issue 93 Pages 11-18
As reported in previous paper, the compatibility of natural ventilation and smoke control in the prototype building has been confirmed. Based on the results, in this paper, CFD simulation is used to predict the detail performance of the natural ventilation system. At the same time, the smoke control function is confirmed. According to the prediction, following results can be obtained: When the area ratio of outlet and inlet is greater than 2, natural ventilation rate increases hardly, while as higher as the chimney is, the natural ventilation rate is. In summer since solar altitude is relatively high in Tokyo, the vertical solar radiation-collecting wall cannot get enough solar radiation, which leads the natural ventilation rate around summer decreases. To obtain stable ventilation rate throughout the year, performance improved type is proposed with inclining the mainly solar radiation-collecting wall. Comparing Tokyo with London, because the latitude of London is higher than Tokyo, the vertical solar radiation-collecting wall can get more solar radiation and stable ventilation rate throughout the year can be obtained in prototype as it is. In addition, the effect of wind on ventilation performance is analyzed. When outside velocity is lower than 1m/s, stack ventilation is dominant, when outside velocity is greater than 2m/s, wind ventilation becomes prevailing. To obtain stable ventilation rate, it is important to grasp the wind information of the region and properly arrange the inlets and outlets.
