LES simulation of an ultra-micro combustion chamber based on a 177 reactions mechanism

Goal of this paper is to investigate the performance of microcombustors, a field currently under rapid development in particular for propulsion, e.g., UAVs and micro-electrical power generators. This study focuses on a cylindrical microcombustor fed by methane and air, with diameter and height 0.025m and 0.06m respectively. A 3D LES simulation with the WALE subgrid scale models, the EDC combustion-chemistry model and the reduced GRIMech1.2 mechanism has been performed. The calculated maximum temperature inside the chamber, the gas exhaust temperature and the combustion efficiency are compared and discussed. Reported results are at 0.05s, that is after 5 residence times. This ultra-microcombustor displays an excellent combustion efficiency which makes it a suitable for application in ultrasmall energy producing devices. This work is part of a broader work that includes an experimental analysis, and it was conceived as a contribution towards a better understanding of the most convenient simulations guidelines for future microcombustor applications, and to a more accurate estimate of the performance parameters to apply to first-order design procedures. © 2010 by ASME.