Influence of the flammable cloud geometry on the gas explosion effects

Abstract In the context of industrial large cloud explosions such as the Buncefield accident, it is commonly accepted that the flammable cloud spreads over a large area on the ground but has a limited height. This can, therefore, be considered as the limiting dimension of the cloud. In this work at a small scale, Leyer highlighted the influence of the limited height of the flammable cloud in the case of cylindrical cloud explosions. Without prejudging the combustion mechanisms, this paper aims to present the influence of this limited dimension of the flammable cloud on the flame dynamics to assess more precisely the overpressure distances of a UVCE by better determining the energy involved in the explosion. The analysis is based on comparing the flame position over time from the fast video films and the overpressure signals recorded in the flammable clouds. The explosions examined are methane and hydrogen‐free jets, methane jets interacting with the ground and rows of obstacles, and large propane clouds obstructed by rows of tree trunks.