Fire Safety Science Digital Archive

Some simplifications have been introduced in the classical models to describe the evolution of fires. They have been applied to single room compartments, obtaining a significant reduction in the computer time required. The heat equation is solved in solid walls and ceiling by using a global energy conservation equation which utilizes the whole history, from the beginning of the fire, of the temperature at the hot surfaces of the walls. An algorithm has been used to avoid the storage of all the values of this surface temperature. Another simplification consists in a systematic treatment of the radiative heat transfer between the different elements, which is based on the assumption that they form a closed surface and that the energies reflected from and transmitted through the flame are small compared to the energy that it emits; this assumption may be acceptable in many cases of interest. A computer code has been developed to predict the evolution of fires, including the above mentioned simplifications; although a more complete validation of the code is necessary, preliminary comparisons with other codes and experiments have been satisfactory.