Unsteady Pool Fires Experiments and Modeling

Abstract

This thesis constitutes an investigation of the behavior of unsteady pool fires newlineand the development of an unsteady model to capture the temporal behavior of newlineopen pool fires taking into account the effect of various control parameters such newlineas fuel depth, pan material, pan diameter, initial fuel temperature, thermochemical newlineand transport properties of fuels and ambient pressure, The experimental studies have been conducted on pool fires with 0.1 to 2 m diameter newlinepans with depths of 40, 50, 60, and 90 mm with n-heptane fuel depths of newline10, 20, and 30 mm without water, some experiments on n-heptane fuel floated newlineon water and also experiments in 0.2 m diameter pan with kerosene, diesel, newlineethanol, and methanol fuel depths of 10 and 20 mm without water in a large newlineindoor fire laboratory. Pans of 0.2 m diameter are made of glass, stainless steel, newlinemild steel, and aluminum and larger diameter pans only of mild steel. More newlineAbstract newlinethan seventy experiments have been conducted with n-heptane include some newlinewith initial fuel temperatures of 290, 319, and 343 K as also experiments with newlinekerosene, diesel, ethanol, and methanol at ambient temperature. Data on the newlinetemporal evolution of mass burn, pan wall temperatures, temperatures inside newlinethe liquid at some depths, and gas phase temperatures at select heights from newlinethe pool surface have been obtained from the experiments. These experiments newlinewere extended to fuels like diesel, kerosene, methyl, and ethyl alcohols. newlineOne general result of significance from the experiments on pans with diameters newlineup to 0.2 m is that the mass flux at the initial burning phase which is largely newlinecontrolled by convection remains the same irrespective of the type of fuel, pan newlinematerial, and fuel depth. Such a feature is valid for larger pan sizes as well, newlineexcept that the burn flux transitions to larger values much earlier. Thus, the major contributions of the work are: newline(a) A correlation that allows the prediction of mean burn flux for unsteady and newlinesteady burning pool fires over a wide range of parameters, newline(b) A detailed