Application of ESCIMO Theory to Turbulent Reacting Mixing Layers
The ESCIMO theory of turbulent combustion is applied to turbulent plane reacting mixing layers. A set of transport equations describing population distributions of folds in such layers is solved, taking into account the property variation in the cross-stream direction.
Simplifications, made in the interest of reducing the computational task, include the following: (1) Fold properties depend on age alone, at a given point in the layer. (2) Fold properties at birth can be determined by tracking upstream along a trajectory of constant mean mixture fraction. (3) Fold size at birth is proportional to the local length scale of turbulence. (4) Fold-formation rate is proportional to the entrainment rate, with further assumptions for its distribution across the layer. (5) Fold-stretching rate is proportional to the time-mean velocity gradient.
The results are presented in the form of population-distribution functions for fold age, and of the mean properties and the fluctuation intensities of scalar quantities in the time-mean flow. The latter are compared with the experimental data of Batt (1977). The qualitative agreement between measured and predicted results is acceptable but quantitative discrepancies exist in the fluctuation intensities of temperature.
KeywordsMixture Fraction Fluctuation Intensity Turbulent Combustion Entrainment Rate Turbulent Shear Layer
Unable to display preview. Download preview PDF.
- 1.D. B. Spalding, The influences of laminar transport and chemical kinetics on the time-mean reaction rate in a turbulent flame, in: Seventeenth (Int.) Symp. on Combust, pp. 431–440, The Combustion Institute, Pittsburgh, PA (1979).Google Scholar
- 2.A. S. C. Ma, M. A. Noseir, and D. B. Spalding, An application of the ESCIMO theory of turbulent combustion. Paper presented at the AIAA Aerospace Science Meeting, January 1980, Pasadena, California (1980).Google Scholar
- 4.S. V. Patankar and D. B. Spalding, Heat and Mass Transfer in Boundary Layers, 2nd edn., Intertext Books, London (1970).Google Scholar
- 6.A. S. C. Ma, D. B. Spalding, and R. L. T. Sun, Application of “ESCIMO” to the turbulent hydrogen-air diffusion flame, in: Nineteenth (Int.) Symp. on Combust., The Combustion Institute, Pittsburgh, PA (1982) (to appear).Google Scholar
- 8.R. L. T. Sun, Application of “ESCIMO” Theory to Turbulent Diffusion Flames, Ph.D thesis, University of London (1982).Google Scholar
- 10.D. B. Spalding, GENMIX. A General Computer Program for Two-Dimensional Parabolic Phenomena, Pergamon Press, Oxford (1978).Google Scholar
- 11.H. E. Fiedler, On turbulent structure and mixing mechanism in free turbulent-shear flows, in: Turbulent Mixing in Nonreactive and Reactive Flows, A Project SQUID Workshop, pp. 381–410, Plenum Press, New York (1975).Google Scholar