Ignition and Propagation of Combustion Waves in a Two-Dimensional Channel. Part I
A. A. Boriskin, A. A. Vasilyev
Lavrentyev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: spark ignition, critical ignition energy of the mixture, laminar and turbulent combustion, normal flame speed, characteristic combustion instabilities, combustion-to-detonation transition
Abstract
Despite numerous studies, many aspects of ignition and propagation of combustion and detonation waves in combustible mixtures remain insufficiently understood, complicating the scientifically sound management of such processes. This paper presents new data on the various stages of ignition and flame front propagation in a flat (two-dimensional) channel of constant cross-section. The experimentally observed main flame instabilities (manifested in the significant non-uniformity and non-stationarity of the combustion front), the phenomenon of flame blowoff (disappearance of glow), and the effect of flame transition to a self-sustaining propagation mode are discussed. Attention is drawn to the problems of the emergence of new ignition sources in the flame front, including explosive micro-sources that facilitate the subsequent transition of combustion to detonation. A number of new features in the physics and dynamics of flame propagation are identified.
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