Combustor Monolith Continuum Model

In the continuum model approach, the two-dimensional temperature equation under the finite volume approach for the entire monolithic structure of the honeycomb catalytic combustor was solved in cylindrical coordinates  

By choosing a time step for the transient solid temperature equation long enough for gas-phase equilibration, the discretized, time-independent set of the Navier-Stokes equations under the boundary layer approximation can be solved for the flow field inside the catalytic channels [12] (quasisteady assumption for the gas-phase) using the CRESLAF package [13]. The applicability of the boundary layer approach in catalytic combustion at sufficiently large Reynolds numbers (Re 20) has already been demonstrated [14]. The simplified equations thus become  

After each time step, the resulting axial temperature profiles from Eq. (3.22) at the radial positions corresponding to the positions of the representative channels simulated were applied as boundary conditions for the individual flow field channel calculations. 

Schneider A, Mantzaras J, Eriksson S (2008) Ignition and extinction in catalytic partial oxidation of methane-oxygen mixtures with large H2O and CO2 dilution. Combust Sci Technol 180 89-126 

Karagiannidis S, Mantzaras J, Jackson G, Boulouchos K (2007) Hetero-Zhomogeneous combustion and stability maps in methane-fueled catalytic microreactors. Proc Combust Inst 31 3309-3317 

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Fig. 5.1 Schematic of the continuum model for the combustor monolith structure...

A propane-fueled, catalytic, mesoscale combustor was investigated numerically and expetimentaUy to assess its apphcabihty for a portable, gas-turbine-based power generahon system. After detailed parametric numerical studies of a single catalyhc channel, a subscale model of the metallic catalytic combustor was constructed. Experimental testing verified the suitability of the proposed mesoscale combustor after meeting flie required power output at the nominal mass throughput. A continuum model was used to simulate the two-dimensional temperature field of the monolith and allowed for a detailed description of the heat loss mechanisms in the monolith. 

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