Multiple coupled chemical reactions occurring within strained diffusion layers are key to a wide range of reactive flow problems. An integral approach is presented here to allow calculations of global properties of such reactive layers for complex multistep chemical kinetics and time-varying strain rates. The infinite-degree-of-freedom partial differential equations (PDEs) governing the dynamics of the species concentration profiles for reactants, intermediates, and products as well as the temperature are projected onto a set of ordinary differential equations having just a few degrees of freedom for the evolution of integral moments of these profiles. The presence of multistep reaction kinetics leads to a set of highly coupled nonlinear moment equations. Numerical solutions are presented for four-step methane-air kinetics coupled with thermal nitric oxide kinetics and are compared with direct solutions of the original PDEs. Some properties and numerical illustrations of key features of the internal layer...
[1]
N. Peters.
Numerical and asymptotic analysis of systematically reduced reaction schemes for hydrocarbon flames
,
1985
.
[2]
W. Dahm,et al.
An integral method for mixing, chemical reactions, and extinction in unsteady strained diffusion layers
,
1991
.
[3]
Amable Liñán,et al.
The asymptotic structure of counterflow diffusion flames for large activation energies
,
1974
.
[4]
Robert J. Kee,et al.
The computation of stretched laminar methane-air diffusion flames using a reduced four-step mechanism
,
1987
.
[5]
F. Fendell.
Ignition and extinction in combustion of initially unmixed reactants
,
1965,
Journal of Fluid Mechanics.