素反応モデルを用いた対向流拡散火炎の消炎に対する統一的解釈に関する研究  [in Japanese] Proposal of Universal Dimensionless Parameter for Extinction of Counter Flow Diffusion Flame via Elementary Reaction Model  [in Japanese]

In this article a unique universal criterion which describes extinction of counter flow diffusion flame was proposed. A numerical study for extinction of counter flow diffusion flame under various conditions of ambient temperature, oxidizer concentration and fuel concentration was performed. The numerical simulations include detailed chemistry in terms of a set of elementary reactions using up to 102 elementary reactions, as well as multi-species transport model. First, detailed flame structures such as distributions of temperature, species and heat release rate under the prescribed various conditions were clarified. An ultimate aim of the present study is at finding a universal criterion of extinction under the general conditions. To this end, we proposed a new parameter "Reaction Zone Damkohler Number", Dr, which is defined as the ratio of the energy flux to the heat release rate at the reaction zone. The maximum flame temperature was plotted against this Dr and it was found that extinction occurs at nearly constant value of Dr, which implies this parameter can be utilized as a criterion for extinction. Further the relationship between Dr and the usual first Damkohler number D_1 was also suggested.