Flame acceleration and DDT in gas explosions

A qualitative description of flame acceleration (FA) process is presented, which shows a complexity of the processes that can follow a weak ignition in a combustible mixture. Considering the exclusive role of the confinement and obstructions, the main focus is made on the processes of FA and DDT typical for areas with strong confinement and heavy obstructions. Main characteristic combustion regimes are described as well as possible routes for development of FA processes. A framework of ideas and criteria that can be used to evaluate initial and boundary conditions under which FA and DDT may be possible is presented. Limitations and uncertainties of these criteria are discussed.