Simulation of the Thermal Response of Ordnance Immersed in Large Aviation Fuel Fires.
NAVAL WEAPONS LAB DAHLGREN VA
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A mathematical model was developed to predict the reaction time of an explosively loaded ordnance item immersed in the flames of a large JP-5 fuel fire. The model, in the form of an explicit finite-difference approximation, is applicable to calculating a one-dimensional, transient temperature distribution in a multi-layered flat-plate analog. Within each layer of the analog, internal energy may be locally generated or absorbed. To verify the utility of the general mathematical model, it was applied to some specific situations in which H-6 loaded MARK 81 and MARK 82 bombs were enveloped by large JP-5 aviation fuel fires. The thermally induced reaction times and the dominant thermal responses of these flame enveloped bombs were successfully predicted by digital computer simulation. A portion of each bomb was represented by a three-layered flat-plate analog which consisted of layers of steel, asphaltic compound, and explosive in perfect thermal contact. A bomb was said to undergo reaction to cook-off whenever the explosvie layer began a thermally induced, exothermic, runaway decomposition. The decomposition process of the explosive was assumed to be governed by a first-order Arrhenius rate equation. Author
- Safety Engineering
- Aerial Bombs