Ultrafine Particulate Matter in Methane-Air Premixed Flames With Oxygen Enrichment

A complementary computational and experimental study is carried out on the formation of ultrafine particulate matter in premixed laminar methane air flames. Specifically, soot examined stretch-stabilized flames to observe inception growth at relatively high flame temperatures common oxygen enriched applications. Particle size distribution functions (PSDF) measured by mobility sizing show clear trends as equivalence ratio increases from Φ = 2.2 2.4. For a given ratio, decreases median particle maximum temperature approximately 1,950–2,050 K. The 20 nm or less for all conditions studied. volume fraction with increasing conditions. condition close limit both number density decrease monotonically temperature. higher peak 2,000 K which may indicate competing processes are optimized this Flame structure computations using detailed gas-phase combustion chemistry Appel, Bockhorn, Frenklach (ABF) model examine connection observed PSDF precursor chemistry. Agreement between computed standoff distances indicates that ABF could provide reasonable prediction currently To first order, be understood terms benzene, naphthalene other precursors. Results current inform behavior natural gas applications elevated