Study On Architecture Fire Simulation Based On FDS

Fire embraces nearly all the effects found in subsonic chemically reacting flow. It is a sophisticated problem involving many phsical and chemical processes. Of great importance to the spread and control of fire is the smoke flow in fire, which due to the complex characteristic of fireis often turbulence. Therefore, the success of fire simulation will depend directly on the accurate modeling of turbulence. Currently, two approaches are often employed to model turbulence:Reynolds-averaged Navier-Stokes Equations method (RANS) and Large Eddy Simulation method (LES). The predictions of many important problems made by RANS are not satisfactory, while LES is becoming more and more important in fire simulation because of its budget between accuracy and cost. LES, however, has a strict demand for grids, especially near rigid wash.The new models are applied to a natural convection problem and a forced convection problem, respectively to test their performances. The calculations are carried out using various grid conditions. When compared with the calculation results of LES and experimental data, the results obtained with the hybrid models agree quite well with the experimental data and are at least not worse than those of LES, while using less grids than LES. Furthermore, the new hybrid models are employed to simulate two typical fire scenarios: Steckler room fire and shopping mall fire. The results give correctly the profile of temperature and velocity in the fires. All these show that the hybrid models developed in this thesis are suitable for the simulation of such complicated problem as fire, which is characterized by high Reynolds number and commonly-found walls.