Flame acceleration in channels with obstacles in the deflagration-to-detonation transition
Artikel i vetenskaplig tidskrift, 2010

It was demonstrated recently in Bychkov et al. [Bychkov et al., Phys. Rev. Lett. 101 (2008) 1645011, that the physical mechanism of flame acceleration in channels with obstacles is qualitatively different from the classical Shelkin mechanism. The new mechanism is much stronger, and is independent of the Reynolds number. The present study provides details of the theory and numerical modeling of the flame acceleration. It is shown theoretically and computationally that flame acceleration progresses noticeably faster in the axisymmetric cylindrical geometry as compared to the planar one, and that the acceleration rate reduces with increasing Mach number and thereby the gas compressibility. Furthermore, the velocity of the accelerating flame saturates to a constant value that is supersonic with respect to the wall. The saturation state can be correlated to the Chapman-Jouguet deflagration as well as the fast flames observed in experiments. The possibility of transition from deflagration-to-detonation in the obstructed channels is demonstrated. (C) 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

gas

Flame acceleration

mixture

walls

flow

tubes

Flame-obstacle interaction

Deflagration-to-detonation transition

nonslip

large-eddy simulation

radiated sound

ddt

Författare

D. M. Valiev

Umeå universitet

V. Bychkov

Umeå universitet

V. Akkerman

Princeton University

C. K. Law

Princeton University

Lars-Erik Eriksson

Chalmers, Tillämpad mekanik, Strömningslära

Combustion and Flame

0010-2180 (ISSN)

Vol. 157 1012-1021

Ämneskategorier

Strömningsmekanik och akustik

DOI

10.1016/j.combustflame.2009.12.021