Computer calculation of concentrations of flame gas species and metal atoms in the nitrous oxide-acetylene and air-acetylene flames

Abstract

A computer method based on the principle of the minimisation of free energy is used to calculate the concentrations of both flame gas and condensed species in flames in thermal equilibrium. The degrees of atomisation of aluminium and silicon are calculated for various fuel-lean, stoichiometric and fuel-rich nitrous oxide-acetylene and air-acetylene flames over a range of temperatures and are found to be both critically dependent on the carbon : total oxygen ratio. When this ratio exceeds unity, the degrees of atomisation are a maximum. The concentrations of 43 species and their dependence on the concentrations of atomic aluminium and silicon are considered, and a comparison is made with the nitrous oxide-acetylene and air-acetylene premixed flames used in practice.