Catalytic combustion has been well studied over several decades . The technique promotes oxidation of the fuel mixture contains the catalysts or by inserting the mixture into a catalytic reactor. A premixed lean fuel/air mixture is burnt in the catalytic reactor, which enables complete combustion at relatively low temperatures, thus reducing CO, and unburned hydrocarbon emissions. Consequently, the formation of thermal NOx is also reduced.

With the use of porous burners, a better stabilization of the premixed  flames can be achieved because porous materials enhance momentum transfer, heat transfer, and also mass transfer leading to an increase in the fame speed. Porous burners have been encouraged by lower emissions as well as by highly efficient characteristics.

The wire/rod-type catalytic reactor is a simple geometry reactor with an economical design with less pressure loss. For the single rod in the reaction channel, the flow characteristic and the difference of conversion efficiency between non-gas-phase reaction and gas-phase reaction have been delineated in the present study. The flow field and the chemical reactions were numerically modeled using 2D Large Eddy Simulation combined with the gas-phase and surface reaction mechanisms. The results show that the current numerical simulation has been validated to precisely predict the vortex shedding and its frequency in the cold flows. Despite the variation trends being dominated by the upstream flow, the vortex shedding phenomena were affected by the flue gas generated from the rod surface. It can be seen from the linear relationship between the vortex shedding frequency of reacting flow and Reynolds Number. It is noted that the vortex shedding vanished if the gas-phase reaction was ignited in the reaction channel. In addition, the geometric modified conversion efficiency was proposed to delineate an indicator that could be potential for the optimization of rod-type catalytic reactor. In summary, the fundamental study of a rod in a 2D flow channel can provide information for optimizing the catalytic design or the rod array arrangement in the reactor. Moreover, the rod can also be a partial catalytic flame holder to ignite and stabilize the gas-phase reaction. The obtained results could be the potential for practical applications of rod-type catalytic combustion, catalytic gas turbine, hydrogen generation, partially catalytic reaction flame holder, and other catalytic reactions that can be appreciated.