(156f) Coupling Micro and Macroscale in Combustion in Porous Media

Many situations involve combustion in porous media, such as waste disposal, fire hazards, or the burning of poor or good quality solid fuels (coal, wood, lignite, oil shales). These processes take place in complex geometries on the microscopic scale, and they involve many transport phenomena, coupled with various chemical reactions, which makes a detailed description difficult.

The aim of this communication is to show how we have treated this issue, by coupling the two scales:

- microscopic in the zone where strong gradients exist, i.e combustion zone,

- macroscopic when the use of Darcy-Scale equations can be done.

Some results of microscale simulations will be given to explain the variety of regimes which can exist in combustion in porous media. Then, a method to estimate a global dispersion coefficient in the local equilibrium approach will be explained and some simulations performed using that coupling approach will be shown.