The Effect of Exhaust Gas Recirculation and Turbulence on the Burning Velocity, Dead Space Thickness, and Minimum Ignition Energy in Premixed Methane-Air Combustion

Abstract

The dilution of a homogeneous combustible mixture with products of combustion has proven to be a successful method of reducing the oxides of nitrogen produced by a combustion process. The Exhaust Gas Recirculation (EGR) affects the flame velocity, ignition energy, and quenching behavior. An experimental program has been conducted to determine the effects of EGR on these fundamental aspects of a turbulent methane/air flame in a constant volume bomb. Data are presented showing that the decrease in flame velocity caused by the EGR can to some extent be compensated for by an increase in the turbulence intensity at a price of increased ignition difficulty. The effect of the EGR, as determined from both heat transfer and ionization measurements, is to increase the single-wall quenching distance.