Modeling urban fire spread based on specific characteristics of substandard housing in Spain

Abstract

Due to the increasing urbanization and development of denser cities, the risk of fire is becoming a significant issue. Different approaches can be found when trying to evaluate the risk of fire and several urban fire spread models have been proposed. However, these models present numerous vulnerabilities, like radiation exposure, direct flame contact, influence of wind, transport of firebrands, amongst others. Nowadays, in Spain there are more than 1.5 million families living in substandard housing. The use of unstable stoves for cooking, lighting, and heating, unsafe electrical connections, along with an excess of combustible materials, contribute to a higher risk of fire. A realistic behaviour of the fire dynamics, with specific values of heat release rates and spread rates, in this type of substandard housing is needed when developing urban fire-spread models. Real data is being recorded from marginal neighbourhoods in Madrid (Spain), with the aim to develop more accurate numerical simulations of the fire dynamics. These models are implemented in Fire Dynamics Simulator (FDS), which is a computational fluid dynamics (CFD) model of fire-driven fluid flow. These predictions are coupled with an urban fire spread model, assessing fire temperatures and heat evolution for this type of housing. The influence of real-time wind is introduced to better evaluate how it influences fire spread between buildings.