Flame emissivity is an important parameter in the study of pool fires. A series of pool fire experiments are carried out with four different fuels namely diesel, gasoline, hexane and kerosene for pool diameters of 0.10 m, 0.13 m and 0.20 m. Flame emissivity at a height of 0.25 times the pool diameter from the base is measured by observing the flame with reference to a black body using infrared camera. Influence of pool diameter (0.3 m, 0.34 m, 0.5 m, 0.7 m and 1.0 m) on flame emissivity at a height of 0.25 times the pool diameter is studied with diesel as the fuel. Variation of flame emissivity with the height of the flame along the center of diesel pool fire is investigated for diameters of 0.3 m, 0.5 m, 0.7 m and 1.0 m. It is observed that the flame emissivity is less at the tip of the flame in comparison with that at the base of the pool fire. The measurement of flame emissivity by observing flame with reference to a black body using infrared camera is corroborated with the measurements conducted with reference to an electrically heated black body for diesel pool fires with diameters 0.3 m, 0.5 m and 0.7 m. Flame emissivity is also inferred from the mass burning rate measurements for diesel oil pool fires of 0.3 m, 0.5 m, 0.7 m and 1.0 m diameters. Flame emissivities are independent of the measurement method. Temperature and surface emissive power distributions of the diesel pool fires for diameters 0.3 m, 0.5 m, 0.7 m and 1.0 m are computed using infrared thermography.

Radiative properties such as temperature and emissive power distributions are very essential for fire safety measurements. The objective of this study is to characterize these distributions for a gasoline pool fire both experimentally and numerically. Infrared thermal camera is employed for the measurement of temperature distributions of gasoline open pool fires for pool diameters of 0.3, 0.5, 0.7 and 1.0 m. Incident heat flux upon a target is computed using the measured apparent temperature distribution and is validated with Schmidt-Boelter heat flux gauge measurements. Numerical studies are conducted using Fire Dynamics Simulator 5.5.3 version. Heat flux measured of target area is used to validate the numerical simulations with the experimental results. Centerline temperature distribution of numerical simulation and the temperature distribution from the experimental results are compared. It is observed that Fire Dynamics Simulator is capable of simulating the open pool fires even for complex fuels such as gasoline.

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Characterization of the heat transfer to a cask engulfed in pool fire is extremely important. Experiments are carried out on diesel pool fires of diameters 0.5, 0.7, and 1.0 m with stainless steel 304L thermal casks of different sizes. Net surface heat flux on the cask is estimated using one-dimensional inverse heat conduction problem code. Velocities of the pool fires are measured using bidirectional probe to estimate the convective heat transfer coefficient (h). The concept of adiabatic surface temperature, using plate thermometer, is applied to the pool fires and the thermal casks. By employing a mixed boundary condition (adiabatic surface temperature and h) in computational fluid dynamics package, transient temperature and heat flux of the cask are estimated. These predicted data are within 10% of the experimental results. This study demonstrates that the transient adiabatic surface temperature of the pool fire can be used to predict the behavior of the thermal cask engulfed in an open pool fire.

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