Abstract
This study is performed to examine experimentally the effects of CO_2 as one of EGR gas on the burning velocity of the propane-oxygen-dilution gas premixed meso-scale spherical laminar flames with the flame radius r_f < about 5mm. The mixtures have nearly the same laminar burning velocity (S_<L0>=25cm/s) with different equivalence ratios (φ=0.5-1.4). N_2 is also examined for comparison. The radius and the burning velocity of meso-scale flames are obtained by using sequential schlieren images recorded under appropriate ignition conditions. It was clear that the burning velocity for the mixture diluted with CO_2 at the same r_f and Karlovitz number has tendency to be larger than that with N_2, except for φ=1.4.
