Flame instabilities are well-known phenomena during gas explosions. Numerous publications address intrinsic flame instabilities, Raleigh-Taylor instabilities, thermal-diffusive instabilities and acoustically driven flame instabilities the latter is especially known to affect vented gas explosions. For dust explosions flame instabilities are not considered to play an important role due the intrinsic turbulence being present and therefore overriding any flame instabilities.
The present paper however, addresses two series of experiments where flame instabilities have been observed which affect the course of dust explosions. This has never been recognised or reported upon before. It is important to understand these phenomena in order to be able to predict under which conditions they occur and exactly how they affect the course of explosions.