Numerical study of laminar flame speed of fuel-stratified hydrogen/air flames

摘要: Abstract Numerical studies on hydrogen/air stratified flames in 1-D planar coordinate are performed using a time-accurate and space-adaptive numerical solver A-SURF. A step change equivalence ratio is initialized as fuel stratification. Flame characterizations including consumption speed flame front propagation compared between corresponding homogeneous flames. Two transport models, with equal diffusivity mixture-average assumptions respectively, considered. With assumption stratification thickness larger than thickness, local speeds of identical, indicating that neither thermal effect nor chemical present When reduced to the order difference caused by due different level H radical burnt gas. The same mechanism also leads assumption. In addition, preferential diffusion further increases difference. mainly additional heat release gas assumption, while effect. Hydrodynamic fluid continuity observed both models. Additionally, increasing hydrodynamic reduced. No significant lean flammability extension mixture introduced