DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
Large Eddy Simulation of an ultra-micro combustion chamber
RÉSUMÉ
The goal of this paper is to investigate the performance of microcombustors. Such field is currently under rapid development in particular for propulsion, e.g., for UAVs, and micro-electrical power generators. This study is focused on a cylindrical microcombustor fed by methane and air, with diameter and height 0.025m and 0.06m, respectively. A 3D LES is performed, using the Flamelet model for the combustion and the detailed GRIMech 3.0 mechanism for the chemistry. A preliminary series of non-reacting numerical simulations were necessary to identify the correct methane inlet duct diameter that avoids "reverse ingestion" (air entering the methane duct and premixing with the fuel upstream of the injection point). The maximum temperature inside the chamber, the gas exhaust temperature and pressure and the wall heat flux are reported and discussed. Combustion efficiency is analyzed from an entropy viewpoint. This work is a contribution to a better understanding of the most convenient design guidelines for future microcombustor applications, and to a more accurate estimate of the performance parameters to apply to first-order design.