Explosions in buildings: modeling and interpretation of real accidents

Abstract Real explosions in domestic structures (Rasbash and Stretch, Struct. Eng 1969;47;403–11) and industrial plants (Howard, Loss Prevention 1972;6;68–73) have been analyzed. Deflagration dynamics are solved for enclosures of volumes of 130–8000 m3 for vent release overpressures in the range of 0–0.21 bar, and for different inertia of covers over the venting spaces in the range 0–15 kg/m2. From comparisons of the real explosion data with the modeling of pressure-time behavior during vented gaseous deflagrations according to an earlier lumped parameter theory values of the main parameter, a turbulence factor, χ, are obtained. The results suggest the combustion is highly turbulent for real conditions in domestic structures (turbulence factor χ⩾8 with discharge coefficient μ=0.6) and especially in large-scale enclosures such as a plant, with internal obstacles (turbulence factor χ⩾17). On the basis of the devised effective turbulence factors (the ratio χ/μ) the design procedures for avoiding the development of excessive overpressures during deflagrations, in both domestic and industrial plant, can be improved.