Single Channel Parametric Simulations

Gas-phase chemistry has been shown to affect combustion characteristics in catalytic reactors, even in sub-quenching channel confinements and particularly at elevated pressures [5]. To allow for extended parametric studies, gas-phase chemistry has not been considered. In doing so, a conservative estimate of the stable combustion regimes was obtained, since gas-phase chemistry has been shown to extend the stability limits of catalytic combustors [3]. Finally, mixture-average diffusion provided the gas-phase transport model [6]. 

An orthogonal staggered mesh of 24 x 200 points (in the x- and y-direction, respectively) over half the gas-phase domain with finer spacing near the catalytic walls yielded a grid-independent solution. Two-dimensional solid heat conduction was solved on a uniform grid of 20 x 200 points. Uniform inlet properties were used for temperature, axial velocity and species mass fractions. No-slip was applied for both velocity components at the gas-wall interface (y — b) and zero-Neumann conditions were set at the outlet (x — L) and the plane of symmetry (y = 0). 

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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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