Investigation of bluff-body micro-flameless combustion
Characteristics of lean premixed conventional micro-combustion and lean non-premixed flameless regime of methane/air are investigated in this paper by solving three-dimensional governing equations. At moderate equivalence ratio (Ø = 0.5), standard k-ε and the eddy-dissipation concept are employed to simulate temperature distribution and combustion stability of these models. The effect of bluff-body on the temperature distribution of both conventional and flameless mode is developed. The results show that in the premixed conventional micro-combustion the stability of the flame is increased when a triangular bluff-body is applied. Moreover, micro-flameless combustion is more stable when bluff-body is used. Micro-flameless mode with bluff-body and 7% O2 concentration (when N2 is used as diluent) illustrated better performance than other cases. The maximum temperature in premixed conventional micro-combustion and micro-flameless combustion was recorded 2200 K and 1520 K respectively. Indeed, the flue gas temperature of conventional mode and flameless combustion was 1300 K and 1500 K respectively. The fluctuation of temperature in the conventional micro-combustor wall has negative effects on the combustor and reduces the lifetime of micro-combustor. However, in the micro-flameless mode, the wall temperature is moderate and uniform. The rate of fuel-oxidizer consumption in micro-flameless mode takes longer time and the period of cylinders recharging is prolonged. © 2014 Elsevier Ltd. All rights reserved.
Energy Conversion and Management
Hosseini, S.E., & Wahid, M.A. (2014). Investigation of bluff-body micro-flameless combustion. Energy Conversion and Management, 88: 120-128. doi: 10.1016/j.enconman.2014.08.023.