Turbulent Shear Layer Mixing with Fast Chemical Reactions

A model is proposed for calculating mixing and chemical reactions in the limit of infinitely fast chemical kinetics and negligible heat release, in fully developed turbulent shear layers. The model is based on the assumption that the topology of the interface between the two entrained reactants in the layer, as well as the strain field associated with it, can be described by the similarity laws of the Kolmogorov cascade. The calculation yields the integrated volume fraction across the layer occupied by the chemical product, as a function of the stoichiometric mixture ratio of the reactants carried by the free streams, the velocity ratio of the shear layer, the local Reynolds number, and the Schmidt number of the flow. The results are in good agreement with measurements of the volume fraction occupied by the molecularly mixed fluid in a turbulent shear layer and the amount of chemical product, in both gas phase and liquid phase chemically reacting shear layers