ฉันรักการแปล
Convenient to divide the flame into two zones
1. Preheat zone: little heat is released
2. Reaction zone: most of the chemical energy is released
2.a Thin region of fast chemistry
• Destruction of fuel molecules and creation of intermediate species
• Dominated by bimolecular reactions
• At atmospheric pressure, fast zone is usually less than 1 mm
• Temperature and species concentration gradients are very large
• The large gradients provide the driving forces for the flame to be self-sustaining, i.e. diffusion of heat and radical species from the reaction zone to the preheat zone
2.b Wider region of slow chemistry
• Chemistry is dominated by three-body radical recombination reactions, such as the final burn-out of CO via CO + OH → CO2 + H
• At atmospheric pressure, this zone may extend several mm