平衡法と渦消散コンセプトモデルを組み合わせた燃焼モデルによるCO-H₂-air乱流拡散火炎の数値解析

抄録

This research aims at building a turbulent diffusion combustion model based on chemical equilibrium and kinetics for simplifying complex chemical mechanisms. This paper presents the combustion model based on chemical equilibrium combined with an eddy dissipation concept model (CE-EDC); the model is validated by simulating a CO-H₂-air turbulent diffusion flame. In the CE-EDC model, the reaction rate of fuels and intermediate species are estimated by using the equations of the EDC model. Then, the reacted fuels and intermediate species are assumed to be in chemical equilibrium; the amounts of the other species are determined by the Gibbs free energy minimization method by using the amounts of the reacted fuels, intermediate species, and air as reactants. An advantage of the CE-EDC model is that the amounts of the combustion products can be determined without using detailed chemical mechanisms. Moreover, it can also predict the amounts of the intermediate species. The obtained results are compared with Correa's experimental data and Gran's computational data by using the EDC model, which uses the complex chemical mechanisms. The mole fractions of CO, H₂, H₂O, OH, temperature, and mixture fraction obtained by using our CE-EDC model were in good agreement with these reference data. Using the present CE-EDC model, amounts of combustion products can be calculated by using a reduced chemical mechanism and the Gibbs free energy minimization theory. The accuracy of this model is in the same order as that of the EDC model.