Controlling Combustion and Maximizing Heat Release in a Reacting CompressibleFree Shear Layer

摘要

The objective of this work has been to study the interaction between heat releaseand mixing in compressible shear layers by analysis and computation, with an eye to finding flow configurations that maximize the heat release per unit distance in the stream direction. The principal prediction is that heat release asymmetry across the layer can enhance mixing over the non-heat release case, but the effect appears too small to yield practical benefits at this time. Time dependent, three-dimensional numerical simulations of a shear layer with weak, steady heat release have shown that such heat release need not decrease mixing but the expected increases are also absent, or too small to be detected currently. However, the original non-heat-release theory has been successfully extended to predict the mixing behavior of three-dimensional planar layers and round compressible jets. This bolsters confidence in the generality of the principles underlying the analysis. Invoking a mixing maximum principle, the extended theory gives a satisfactory analytic expression for mixing ratio when M sub c < or = 3. A variational formulation of the heat release problem with a functional dependent on the square of streamline curvature has proved intractable. Shear layer, Compressibility, Mixing, Heat release.