The effects of strain and curvature on the mass burning rate of premixed laminar flames

The Markstein number characterizes the effect that flame stretch has on the burning velocity. Different expressions for this number are deduced from integral analysis. According to a phenomenological law, the Markstein number can be separated into a part for the curvature of the flame and a part for the straining of the flow. This separation is analysed here. It appears that the Markstein number for curvature and the combined one for both curvature and strain are unique. It is, however, not possible to introduce a separate and unique Markstein number for the flow straining that can be used to describe its influence in different combustion situations. The theoretical and numerical analysis is applied to flat steady counterflow flames as well as to steady, imploding and expanding spherical flames.

[1]  Forman A. Williams,et al.  Effects of molecular diffusion and of thermal expansion on the structure and dynamics of premixed flames in turbulent flows of large scale and low intensity , 1982, Journal of Fluid Mechanics.

[2]  H. Markstein Nonsteady flame propagation , 1964 .

[3]  ten Jhm Jan Thije Boonkkamp,et al.  An evaluation of different contributions to flame stretch for stationary premixed flames , 1997 .

[4]  M. Z. Haq,et al.  Laminar burning velocity and Markstein lengths of methane–air mixtures , 2000 .

[5]  Forman A. Williams,et al.  The asymptotic structure of stoichiometric methaneair flames , 1987 .

[6]  S. Davis,et al.  Markstein numbers in counterflow, methane- and propane- air flames: a computational study , 2002 .

[7]  D. Bradley,et al.  The measurement of laminar burning velocities and Markstein numbers for iso-octane-air and iso-octane-n-heptane-air mixtures at elevated temperatures and pressures in an explosion bomb , 1998 .

[8]  Alan Williams,et al.  The use of expanding spherical flames to determine burning velocities and stretch effects in hydrogen/air mixtures , 1991 .

[9]  Bernard J. Matkowsky,et al.  Flames as gasdynamic discontinuities , 1982, Journal of Fluid Mechanics.

[10]  de Lph Philip Goey,et al.  A computational study on propagating spherical and cylindrical premixed flames , 2002 .

[11]  Kendrick Aung,et al.  Flame stretch interactions of laminar premixed hydrogen/air flames at normal temperature and pressure , 1997 .

[12]  P. Clavin,et al.  Flamelet Library for Turbulent Wrinkled Flames , 1989 .

[13]  P. Gaskell,et al.  Burning Velocities, Markstein Lengths, and Flame Quenching for Spherical Methane-Air Flames: A Computational Study , 1996 .

[14]  Chung King Law,et al.  An integral analysis of the structure and propagation of stretched premixed flames , 1988 .

[15]  Fokion N. Egolfopoulos,et al.  Direct experimental determination of laminar flame speeds , 1998 .

[16]  Geoffrey Searby,et al.  Direct and indirect measurements of Markstein numbers of premixed flames , 1990 .

[17]  Piotr Wolanski,et al.  Finding the markstein number using the measurements of expanding spherical laminar flames , 1997 .

[18]  De Goey,et al.  A flamelet description of premixed laminar flames and the relation with flame stretch , 1999 .

[19]  de Lph Philip Goey,et al.  Intrinsic Low-Dimensional Manifold Method Extended with Diffusion , 2002 .

[20]  B. Rogg,et al.  The asymptotic structure of weakly strained stoichiometric methane-air flames , 1990 .

[21]  ten Jhm Jan Thije Boonkkamp,et al.  A Mass-Based Definition of Flame Stretch for Flames with Finite Thickness , 1997 .

[22]  Vincent Giovangigli,et al.  Formulation of the premixed and nonpremixed test problems , 1991 .

[23]  S. Davis,et al.  Determination of Markstein numbers in counterflow premixed flames , 2002 .

[24]  Gerard M. Faeth,et al.  Laminar burning velocities and Markstein numbers of hydrocarbonair flames , 1993 .