Abstract
Gas explosion in confined spaces generates a sudden rise of internal pressure and can result in extensive damage such as destruction of the structure, generation of blast waves, fragment scattering, and heat release. Predicting pressure behavior is necessary for risk assessment and safety management at places, such as chemical plants, where combustible materials are used. In the past, many explosion experiments have been performed and the data such as pressure histories and KG values have been obtained. However, in those experiments, less than tens of liters vessels were used and their volume were very small compared to real cases. It will cause underestimation of the risk to full-scale explosions because the effect of flame instabilities is neglected in small scale experiments. In fact, some studies showed that the flame accelerates in large scale because of instabilities of the flame front. In order to prevent the underestimation of the risk for gas explosions, the effect of flame front instabilities has to be considered. In this study, we considered the effect of the flame front instabilities by regarding the flame front as a fractal structure and proposed a new method which could predict the pressure behavior properly even in a large scale. We verified the accuracy of the new method by experiment. In addition, the correction of the KG value in a large vessel was proposed.
