Turbulent mixing and combustion in a reacting shear layer

The temperature field is investigated in a gaseous mixing layer consisting of low-concentration hydrogen and fluorine. The results show the presence of large, hot structures separated by tongues of cool fluid that enter the layer from either side. The cores of the structures appear to be well mixed. the usual bell-shaped mean temperature profiles result from a duty cycle whereby a given point sees alternating hot and cool fluid, which results in the local mean. The adiabatic flame temperature is not achieved on average at any point across the layer. It is found that, in general, two different mean temperature profiles result from a given set of reactant compositions if the sides of the layer on which they are carried are reversed. These observations are not consistent with gradient diffusion concepts.