FILTRATION COMBUSTION IN MOVING-MEDIA - ONE AND 2 REACTION ZONE STRUCTURES

We demonstrate the existence of both one and two stationary reaction z one structures which arise in filtration combustion in a moving porous medium. This configuration may be important for SHS reactors. Using t he narrow reaction zone approximation, we derive approximate analytica l expressions for the principal combustion characteristics, including the combustion temperature, the temperature and depth of solid convers ion at the first reaction zone, the locations of the reaction zone(s), the inlet and outlet oxidant fluxes, as well as profiles for the spat ial distributions of pressure, temperature, and depth of conversion, c orresponding to the stationary reaction zone structures. We also deter mine the region of existence in parameter space for each solution stru cture. In addition, we numerically simulate the full time-dependent pr oblem, and describe the evolution to steady-state behavior correspondi ng to the stationary two zone structure, thus demonstrating that the s tructure is stable. We find rather good agreement between the analytic al results and those obtained from the simulations. Finally, various p roperties of both the one and two zone structures are described. (C) 1 997 by The Combustion Institute.