A prediction of the thermal response of a steel beam installed beneath a ceiling and exposed to a localized fire source was performed by using CFD model. The validity of this calculation has been verified by results of experiments. Concerning the heat flux, the difference between analytical results and experimental values increases with increasing dimensionless heat release rate QHB*≡Q/ρCPT0 g1/2HB5/2. In the case of the lower flange, the difference between the analytical result and experimental value increases rapidly over the range of QHB* from 0.3 to 0.5, reaching the maximum value of about 27(kW/m²). From the results of the investigation, it has become clear that the prediction is possible with a practical accuracy about the convection part of heat transfer. However, it is necessary to model minutely about combustion and radiation.
The present paper concerns a performance-based fire safety analysis and design of a high-rise building. The resulting fire safety recommendations are compared with those specified by acceptable solutions in terms of the earlier prescriptive building code. The respective risk to life resulting from the analysis is compared and discussed. The benefit and need of using a risk based verification method as a complement to a deterministic fire safety engineering method is demonstrated. The cost-effectiveness of different solutions is also demonstrated. This paper is based on the results from a case-study presented at the 2nd International Conference on Performance-Based Codes and Fire Safety Design Methods in Maui 1998.
A hotel fire occurred in Shirahama, Wakayama prefecture on November 17th 1998. This building fire was one of the widest burning area of building fires in Japan. During this fire, there was high wind velocity at about 7m/sec. At the same time, there was a lot of number of fire brands. We surveyed the distribution of fire brands and spot fires due to this fire by exploration and questionnaire. As a consequence, it was found that through exploration and questionnaire that there is a relation between the distribution of fire brands and the size of fire brands etc.
At present, the CFD method of fire modelling is a useful and the most detailed tool for the fire safety analysis. In this paper the CFD modelling of real experimental fire in a garage compartment and its gaseous extinguishing are described. The numerical model is based on the three-dimensional incompressible Navier-Stokes equation set, K-E turbulence model with wall functions, Eddy Break-Up combustion model. The radiation heat transfer was taken into account as a heat sink term. The extinguishing was modelled by means of simple and reliable phenomenological model based on the value of flame extinguishing concentration of suppression agent. The application of extinguishing model allowed to describe the process of fire suppression, including behavior of heat release rate and time of extinguishing. The detailed information about distribution of suppressant concentration, which generally depends on temperature and velocity fields in compartment, was obtained during numerical simulation. The solution obtained was compared with available analytical and experimental data.