Abstract
We formulate a two-dimensional model describing the combustion of porous condensed phase materials in which a reactant melts and spreads through the void space of a porous solid. The melt may completely fill the pores, or some gas may remain in the pores. In each case, the volume fraction of melt is prescribed. In the limit of large activation energy, we analytically find a one-dimensional basic state consisting of a uniformly propagating combustion wave with a planar reaction front and a planar melting front. We find that the uniformly propagating solution with planar fronts is linearly unstable to traveling waves transverse to the propagation direction of the basic state above some critical Zeldovich number. The critical wave number associated with this critical Zeldovich number is generally unique and nonzero. However, the critical wave number can be zero for certain parameter values. For other special parameter values, the neutral stability curve may have two minima, so that two wave numbers lose stability at the same Zeldovich number.
Original language | English (US) |
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Pages (from-to) | 4443-4462 |
Number of pages | 20 |
Journal | Chemical Engineering Science |
Volume | 51 |
Issue number | 19 |
DOIs | |
State | Published - Oct 1996 |
Funding
Combustion in gasless systems is generally accompanied by melting of one or more of the components of either the initial mixture or the intermediate or final products. This is due to the large exothermicities and the resulting high combustion temperatures for most such mixtures. Melting with subsequent spreading of the melt increases the surface-to-surface contact of the reactants which significantly promotes the reaction. Gasless systems in which melting does not occur typically cannot sustain a combustion wave because of * Supported by a NASA Graduate Student Research Fellowship. * Supported in part by NSF Grant 9308708 and NASA Grant NAG3-1608.
Keywords
- Gasless combustion
- SHS
- melting
- porous medium combustion
- stability
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Industrial and Manufacturing Engineering