More than 1 billion people are living in informal settlements and refugee camps where houses are commonly built from thermally-thin materials (e.g. steel/asbestos sheets). In fire safety literature there is insufficient attention describing the required conditions for flashover (e.g. Heat Release Rate needed for flashover,̇) in such compartments. In this work, ̇ and heat fluxes to the surroundings for compartments with thermally-thin boundaries were investigated using eight compartment fire tests built with 0.5 mm steel sheets and four fuel loads. Numerical simulations were conducted to validate FDS for this application, using the heat release rate inside and outside the compartment, the gas layer temperature and the heat fluxes to the surroundings. The validated model was employed to conduct demonstrative sensitivity and parametric studies to understand the heat balance for thermally-thin under-ventilated compartments. It was found that the heat transfer on/from the walls of the compartment is dominated by radiation, in contrast to the compartments with thermally thick boundaries where the wall conduction dominates. The radiative heat transfer coefficient hrad was then resolved numerically and correlated against the gas layer temperature, wall temperatures and the ̇ to create a semi empirical correlation for estimating the ̇.

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This paper presents correlations for the weighted-sum-of-gray-gases (WSGG) model for carbon monoxide based on HITEMP2010. The correlations are valid for pressure path lengths from 0.0001 atm·m up to 10 atm·m, total pressure in the order of 1.0 atm, and for temperatures ranging from 400 K up to 2500 K. Some test cases embodying nonhomogeneous, nonisothermal conditions are presented, and the results for the WSGG model are compared with the line-by-line (LBL) solutions for CO.

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This work numerically investigates the effects of turbulators at the air and fuel (methane) inlets on the thermal behavior of a combustion chamber. Conservation equations for mass, momentum, energy, gaseous chemical species, soot, and temperature fluctuation variance in cylindrical axysimmetric coordinates were solved using the finite volume method. Chemical reaction rates were computed through the Arrhenius-Magnussen model, with two-step combustion reaction. The turbulence closure model, to compute the turbulent viscosity, was the standard κ-ε. The modeling of turbulence-radiation interactions (TRI) considered the absorption coefficient-temperature correlation and the temperature self-correlation. The radiative heat source was calculated using the discrete ordinates method, considering the weighted-sum-of-gray-gases (WSGG) model with the superposition method to compute the radiation from the gaseous species and soot. The effect of inlet turbulators was studied by varying the turbulence intensity of both inlet streams (air and fuel), encompassing mild to severe turbulators (TI = 3%, 6%, 15%, 20%). The results showed that temperature and radiative heat source fields, and heat transfer rates on the chamber wall and radiative fraction were importantly affected by the different turbulators intensities (e.g. radiative fraction was increased from 20.6% to 32.8% when the turbulence intensity was varied from 3% to 20%). Comparisons of results obtained when TRI modeling was neglected in relation to results obtained when TRI modeling was computed showed that TRI influenced the thermal field (temperature and radiative exchange) in a similar way independently of the turbulator intensity (e.g. radiative fraction decreased 20% when TRI modeling was neglected, for both turbulators intensities).