Resumen de Combustion in hydraulically resisted flows

Gregory I. Sivashinsky

• The effects of hydraulic resistance on premixed gas combustion in tubes and inert porous beds are discussed on the basis of recent research. It is found that the hydraulic resistance causes a gradual precompression and preheating of the unburned gas adjacent to the advancing deflagration which may lead (after an extended induction period) to a localized thermal explosion triggering an abrupt transition from deglagrative to detonative combustion. The hydraulic resistance has a profound effect also on the structure and velocity of well-settled detonation. At a sufficiently high level of resistance the normal near Chapman-Jouguet detonation is found to undergo a jumpwise hysteretic transition to a low-velocity detonation driven by the developing pressure diffusivity. The lattter mode may even become subsonic, the phenomenon occasionally observed in porous bed combustion.