Comparison of Explosion Methods for Large-Scale Unconfined Elongated Explosions with Propane and Methane mixtures

PresentationExisting methods for flame propagation and deflagration to detonation transition (DDT) prediction can be divided into three main categories: empirical models, phenomenological and Computational Fluid Dynamics (CFD) based. The former relies on correlations derived from experimental tests and are usually very simple and fast to apply. Phenomenological methods are simplified models which represent the major physical processes in the explosion. CFD-based models, on the other hand, are more sophisticated and require a high degree of expertise for its usage and data analysis. Although all three types of methods are extremely useful for overpressure and flame speed prediction in scenarios involving accidental industrial explosions, they usually fail to predict the occurrence of deflagration-to-detonation transition (DDT) and flame acceleration for low and medium reactivity fuels, such as propane and methane, in elongated clouds. This can be related to the fact that detonation onset or highly turbulent flames are often ignored for such types of fuel. Having that in mind, this paper aims to conduct a review of current explosion models and compare them to recent large-scale tests with premixed propane-air and methane-air mixtures. The ultimate goal is to identify main flame parameters to be included in explosion analysis and propose modifications to improve overpressure and flame speed prediction for elongated vapor clouds