A priori testing of a similarity model for large eddysimulations of turbulent premixed combustion

Large eddy simulation, where large coherent structures are explicitly computed whereas the effects ofsmaller ones are modeled, appears as a very promising tool to numerically describe turbulent combustion. However, this approach requires the modeling of the unresolved reaction rate (i.e., reaction rate at scales unresolved during the simulation). In this paper, a similarity model, where the unresolved scales are assumed to behave like scales slightly larger than the cutoff scale, is proposed to estimate the subgridscale flame surface density. The model parameter is modeled assuming that the flame front behaves like a fractal surface at scales larger than a cutoff scale of the order of the laminar flame thickness. This model is tested against experimental data obtained using planar laser-induced fluorescence on the OH radical in a turbulent premixed propane/air flame. Promising results are found: the similarity model reproduces correctly the locations of the unresolved reaction rate, whereas the fractal scaling analysis provides a very good estimate of the model parameter.

[1]  Charles Meneveau,et al.  The fractal facets of turbulence , 1986, Journal of Fluid Mechanics.

[2]  D. Veynante,et al.  Large eddy simulations of an acoustically excited turbulent premixed flame , 2000 .

[3]  Tadao Takeno,et al.  Fractal-like character of flamelets in turbulent premixed combustion , 1989 .

[4]  N. Peters.  Laminar flamelet concepts in turbulent combustion , 1988 .

[5]  Benoit B. Mandelbrot,et al.  Fractal Geometry of Nature , 1984 .

[6]  F. Ducros,et al.  A thickened flame model for large eddy simulations of turbulent premixed combustion , 2000 .

[7]  D. Veynante,et al.  Direct numerical simulation analysis of flame surface density concept for large eddy simulation of turbulent premixed combustion , 1998 .

[8]  Roger E. A. Arndt,et al.  Advances in Turbulence , 1988, Lecture Notes in Mechanical Engineering.

[9]  T. Poinsot,et al.  Theoretical and numerical combustion , 2001 .

[10]  Ömer L. Gülder,et al.  Turbulent premixed combustion modelling using fractal geometry , 1991 .

[11]  A. Kerstein,et al.  Field equation for interface propagation in an unsteady homogeneous flow field. , 1988, Physical review. A, General physics.

[12]  RS Cant,et al.  Implications of a flame surface density approach to large eddy simulation of premixed turbulent combustion , 2001 .

[13]  Paul A. Libby,et al.  The Interaction Between Turbulence and Chemistry in Premixed Turbulent Flames , 1989 .

[14]  H. V. Gelder.  The Netherlands , 2004, Constitutions of Europe (2 vols.).

[15]  Alan R. Kerstein,et al.  Stochastic simulation of the structure and propagation rate of turbulent premixed flames , 1992 .

[16]  F. Gouldin.  An application of fractals to modeling premixed turbulent flames , 1987 .

[17]  H. Tsuji,et al.  Fractal Geometry Application in Estimation of Turbulent Burning Velocity of Wrinkled Laminar Flame , 1994 .

[18]  Rs Cant,et al.  A flame surface density approach to large-eddy simulation of premixed turbulent combustion , 2000 .

[19]  G. Karami.  Lecture Notes in Engineering , 1989 .

[20]  Ömer L. Gülder,et al.  Inner cutoff scale of flame surface wrinkling in turbulent premixed flames , 1995 .