Numerical studies on fire-induced flow in a highrise residential building

In contrast to commercial buildings, most of the local highrise residential buildings are designed with openable windows. In case a fire occurs in such a flat with windows opened, convection due to hot indoor smoke and cool outdoor air would take place in regions near the windows. Numerical studies on the fire-induced air velocity, temperature, and pressure fields under steady burning in a highrise building are reported in this paper. A high building with 12 rooms (four storeys and three rows) of length 5 m, width 12 m, and height 15.2 m was considered. Every room is of length 5 m, width 4 m, and height 3.8 m. To allow complete development of the flow at the opening, the computational domain was extended 4 m in length, 2 m in width on both sides, and 5.5 m in height outside the building. A fire of size 0.83 m by 1.2 m by 0.4 m and of constant heat release rate was located. The technique of Computational Fluid Dynamics (CFD) was used. Effects of hot air moving out of a compartment on its adjacent upper level were studied by simulating the amount of hot air moving in and the resultant temperature fields. Results are useful in understanding a highrise building fire and from those predicted velocity, temperature, and pressure fields, workable fire safety design can be made. Extensive simulations were carried out under different conditions.