Short Communication

Abstract

A mixing rule is developed to predict extinction of a diffusion flame burning a multicomponent fuel. The chemical reaction is approximated as a one-step process between each component of the fuel and the oxidizer, and the activation energy characterizing the reaction is presumed to be large. The mixing rule predicts the overall chemical kinetic rate parameters characterizing the gas phase oxidation of the multicomponent fuel, if the rate parameters for its components are known. To test the validity of the predictions, extinction experiments were performed on diffusion flames stabilized above heptane, toluene, methanol, and a number of homogeneous solutions (with different proportions of the components) of these fuels. Experimental and theoretical values for the overall activation energy for the solutions were found to agree to better than 5 percent, and the preexponential factors were found to agree to better than a factor of three.