Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-06-15T18:33:44.358Z Has data issue: false hasContentIssue false

Influence of wrinkled premixed-flame dynamics on large-scale, low-intensity turbulent flow

Published online by Cambridge University Press:  26 April 2006

R. C. Aldredge
Affiliation:
Department of Applied Mechanics and Engineering Sciences, University of California, San Diego, La Jolla, CA 92093–0310, USA
F. A. Williams
Affiliation:
Department of Applied Mechanics and Engineering Sciences, University of California, San Diego, La Jolla, CA 92093–0310, USA

Abstract

Premixed turbulent flame propagation is analysed under the assumptions of stationarity and transverse homogeneity by expansions for small values of the ratio of the turbulence intensity to the laminar burning velocity. For large Zel'dovich numbers, the effects of diffusive—thermal phenomena within the flame, gas expansion, buoyancy and Lewis and Prandtl numbers different from unity are taken into account under the constraint that turbulence scales are large compared with the laminar flame thickness. A general formulation is given, involving solutions through Fourier decompositions. Parametric results for turbulent burning velocities are obtained, and the evolution of components of turbulent kinetic energies through the flame is calculated. It is shown how buoyancy counteracts the tendency for gas expansion to increase transverse components of the turbulent kinetic energy, pressure fluctuations and vorticity generation across the wrinkled flame. Strong readjustments in components of the turbulent kinetic energy are shown to occur in the downstream hydrodynamic zone. It is established that, with the effects of the hydrodynamic zones fully taken into account, the flame can induce anisotropy in initially isotropic turbulence such that the final velocity fluctuations exhibit higher intensities in the longitudinal mode than in transverse modes, while the enhanced vorticity fluctuations are entirely transverse.

Type
Research Article
Copyright
© 1991 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aldredge, R. C. 1990 Theory of premixed flame propagation in large-scale turbulence. Ph.D. thesis, Princeton University.
Batchelor, G. K. 1956 The Theory of Homogeneous Turbulence. Cambridge University Press.
Clavin, P. 1985 Prog. Energy, Combust. Sci. 11, 1.
Clavin, P. & Garcia-Ybarra, P. 1983 J. Méch. Theor. Appl. 2, 245.
Clavin, P. & Williams, F. A. 1979 J. Fluid Mech. 90, 589.
Clavin, P. & Williams, F. A. 1982 J. Fluid Mech. 116, 251.
Hinze, J. O. 1975 Turbulence, 2nd edn. McGraw-Hill.
Pelce, P. & Clavin, P. 1982 J. Fluid Mech. 124, 219.
Searby, G. & Clavin, P. 1986 Combust. Sci. Technol. 46, 167.
Williams, F. A. 1985 Combustion Theory, 2nd edn. Addison-Wesley.