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A ceramic honeycomb was employed in a 1-kW class compact tubular fuel reformer based on noncatalytic partial oxidation (POX) of methanol. POX was stabilized on the outlet surface of the ceramic honeycomb under various experimental conditions with different equivalence ratios (φ) and thermal loads (qload); the latter represents the thermal input to the reformer calculated from the lower heating value (LHV) of methanol. The best performance of the reformer was achieved at φ = 3.5, and the adiabatic flame temperature was achieved. The location where the reaction occurred was determined, and the reaction was found to stabilize at an almost identical location under a wide range of thermal load conditions. This robust feature of the reaction is a significant characteristic of the ceramic honeycomb. By inserting a secondary honeycomb downstream of the reaction region, it was possible to move the reaction region upstream. This shifting of the reaction region was a result of the energy regeneration attributed to t...

Three-dimensional numerical simulation was conducted by making use of a Reynolds Average Navier-Stokes (RANS) approach for the flow in a duct accompanying longitudinal vortices, and discussions are given for the related thermal fields. In the first half of this article, applicability of the turbulence models adopted in the present study is discussed based on the comparison with some published experimental results. The main part of the article treats the numerical results for the flow around a discrete rib attached obliquely to the flow direction onto the bottom wall of a square duct in which a fully developed turbulent flow is established at the inlet. Due to the rib inclination and the gaps existing between the rib ends and the side walls, noticeable heat transfer augmentation is obtained downstream of the rib, produced by a strong secondary flow motion.