Wave sequences for solid fuel adiabatic in-situ combustion in porous media



Document title: Wave sequences for solid fuel adiabatic in-situ combustion in porous media
Journal: Computational & applied mathematics
Database: PERIÓDICA
System number: 000310703
ISSN: 0101-8205
Authors: 1
2
3
Institutions: 1Universidade Federal de Campina Grande, Departamento de Matematica e Estatistica, Campina Grande, Paraiba. Brasil
2University of Alberta, Department of Civil and Environmental Engineering, Edmonton, Alberta. Canadá
3Instituto Nacional de Matematica Pura e Aplicada, Rio de Janeiro. Brasil
Year:
Volumen: 25
Number: 1
Pages: 27-54
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental, aplicado
English abstract We study the Riemann problem with forward combustion due to injection of air into a porous medium containing solid fuel. We neglect air compressibility and heat loss to the rock formation. Given initial reservoir and injection conditions, we prove that there is a unique time asymptotic wave sequence for combustion with complete oxygen consumption. The sequence consists of a region of unburned air at injection temperature, a warming discontinuity, a hot region with unburned air, a combustion wave and a region with burned air and unburned fuel at the initial reservoir temperature. The waves have very different speeds, and therefore they cannot be detected in laboratory experiments that focus on the combustion wave. However, they should occur in field scale. By introducing a cut-off in Arrhenius' law, the reaction rate vanishes at reservoir temperature, and two types of wave sequences are possible. One was already described. The other occurs for incomplete oxygen consumption. In this case, the wave sequence contains another wave, i.e., there is another region ahead of the combustion wave containing incompletely burned air at reservoir temperature, and a gas composition discontinuity that moves fast. However, instead of a unique solution for each Riemann data, there is a one parameter family of wave speeds and strengths. This multiplicity of solutions may to be due to the cut-off
Disciplines: Ingeniería,
Matemáticas
Keyword: Ingeniería de energéticos,
Matemáticas aplicadas,
Combustión,
Medio poroso,
Solución de Riemann,
Inyección de aire
Keyword: Engineering,
Mathematics,
Energy engineering,
Applied mathematics,
Combustion,
Porous media,
Riemann solution,
Air injection
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