Simulação de um incêndio real com os programas Fire Dynamics Simulator© (FDS) e Pyrosim©

Abstract

Computer simulation of buildings in a fire situation can help design passive and active protection measures for buildings, and support forensic investigation work in accidents. In this context, the present work aims to simulate the spread of a fire in an autonomous unit of a multifamily building using the Fire Dynamics Simulator (FDS) and Pyrosim programs. Thus, from the technical visit to the autonomous unit, documentary records were found and the case study was divided into two phases. Phase I corresponded to the analysis of the evidence collected using the scientific method NFPA 921 (2021) to investigate the fire scenario. In addition, Phase II carried out hypothesis testing of the scientific method with computer simulation in the Pyrosim and FDS programs. With the data, in the phase I followed the stage of developing hypotheses whose analysis of the data resulted in the fire sequence of the real fire. Then, in phase II, the thermal properties of the materials, combustion reactions were included and as results the meshes between 0.50m and 0.10m were studied. The results obtained defined a 0.50m mesh for simulations to analyze the input parameters, and a 0.20m mesh for the simulation of the final hypothesis. Furthermore, the results maintained the thermal properties defined in the literature and in the FDS, and define the occurrence of an explosion that corroborated the simulation with the analysis of Phase I. Subsequently, in the simulation of smoke propagation, the horizontal and the height of the smoke layer in the environment (in subways), observing the initial concentration of smoke in the upper layer of the rooms and later descending to the open windows or finished floor. The simulation reproduced the soot spilling onto the half-open window in the laundry room and no broken glass due to the high temperature reached in the living room. Another result was the comparison of equipment and materials that reached their melting or combustion point (partial or complete) with the temperature reached in the FDS simulation. Finally, the simulation had temperature variation per room, reaching 820°C in the living room, whose temperature converges with the carbonization of the wood and thermal breakage of the glass at 300°C, reducing the occurrence of flashover above 600°C in this room. environment. Furthermore, between 227.10°C and 245.90°C were obtained in bedroom 1, confirming the melting point reached between 225-245°C referring to the damaged air conditioning front panel. The same is observed regarding the shower's melting point of 134.15°C with the simulation temperatures between 402.7°C and 316.50°C in the bathroom. Finally, in bedroom 2, the simulation exceeded 160-170°C for the melting point of the polypropylene of the blind installation tape on the window, reaching between 214.50°C and 553.30°C. In view of the above, it is concluded that a computer simulation in Pyrosim and FDS carried out in Phase II, resulted in the smoke path and the temperatures reached converging with the real fire evidence collected in Phase I of the research.