ABSTRACT
A premixed £ame is a de£agration wave that propagates in a mixture comprising a fuel and an oxidant, for example, gasoline and oxygen in the air, respectively, and leaves behind hot, nonreacting combustion products, for example, a mixture of water vapor, carbon dioxide, and nitrogen at a temperature of about 2000 K. The pressure p decreases across the £ame from the unburned to the burned side, but the decrease in p is very weak and is commonly neglected when calculating the temperature T and the density ρ using the ideal gas law. The density drops across the £ame and the density ratio, σ = ρu/ρb, is about 6-8 for a typical burning mixture. Here, the subscripts u and b designate unburned (or fresh) mixture and burned mixture (or products), respectively. The term “burned mixture” means combustion products in the state of chemical equilibrium.
