Smoke spreading along corridor induced by outdoor wind: Numerical simulation and parameter sensitivity analysis

Abstract

During a fire in building of high or low height, 80% of deaths are caused by the inhalation of smoke. Considering the fact that outdoor wind is one of the important driving forces of the smoke movement of the fire, this work investigates its effects on the dynamics of smoke along corridor induced by compartment fire. This study is carried out using numerical simulation based on experimental data. The computational fluid dynamic code used is FDS. Through the analysis of mesh resolution, it is shown that the numerical results can agree well with the experimental data. Simulations are performed with different wind speeds. It can be seen that the outdoor wind has effects on the smoke stratification. Indeed, the more wind speed increase, the more the smoke stratification is disturbed. Under these conditions, smoke occupies entire corridor volume and thus presents a high risk of toxicity to people. It can be found that the temperature of the smoke increases suddenly and decreases to converge to a homogeneous value in the entire enclosure. Considering the importance of the input data used for the numerical simulation, a sensitivity analysis is made on parameters related to the material, fuel, combustion and extinction models. This analysis is carried out using a local sensitivity analysis method. It turns out that mass flux of fuel and activation energy as well as thermal conductivity of the walls have significant effects (more than 10%) on the smoke temperature near the celling.