Combustion and Flame 2018-04-03

Deflagration-to-detonation transition in an unconfined space

Andrey Koksharov, Viatcheslav Bykov, Leonid Kagan, Gregory Sivashinsky

Index: 10.1016/j.combustflame.2018.03.006

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Abstract

Whereas deflagration-to-detonation transition in confined systems is a matter of common knowledge, feasibility of the transition in unconfined space is still a matter of controversy. With a freely expanding self-accelerating spherical flame as an example, it is shown that deflagration-to-detonation transition in unconfined gaseous systems is indeed possible provided the flame is large enough. The transition is caused by positive feedback between the accelerating flame and the flame-driven pressure buildup, which results in the thermal runaway when the flame speed reaches a critical level.