Document Type

Article

Publication Date

2012

Publication Title

Microgravity Science and Technology

Abstract

A compressible model is developed with kinetics based on the Wang–Mou five-step global kinetic scheme and used to evaluate the temperature, concentration, and velocity fields characteristic of low temperature combustion in unstirred static reactors. This work relaxes the assumption of small exothermicity that enabled prior studies to employ the Boussinesq approximation, valid for cases where BT << 1, i.e., slow reactions and cool flames. In this study, the range of validity of the model is extended to cases with large temperature excursions, including multi-stage ignition. For the weakly exothermic cases considered, including modes of slow reaction and cool flames, the Boussinesq approximation is completely adequate. However, it overpredicts the density change and underpredicts the ignition delay time for high-temperature ignitions. Qualitative comparison with experimental results acquired at microgravity conditions are also discussed.

Keywords

Low-temperature combustion, Cool flames, Compressible model, Wang–Mou model, Critical Rayleigh number

Volume

24

Issue

2

First Page

113

Last Page

125

Comments

Originally published in Microgravity Science and Technology, 24(2):113–125.

http://link.springer.com/journal/12217

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