Article révisé par les pairs
Résumé : The effective rate of a chemical reaction is a complex combination of purely chemical effects and of effects related to transport phenomena or, more generally, to the spatial degrees of freedom. This coupling is analyzed in the limiting case of almost ideal mixing, taking into account the spatiotemporal correlations of the turbulent velocity field. A weak-noise expansion permits the deduction of an effective eddy diffusivity which is a function not only of the statistical properties of turbulence but also of the chemical kinetics. An application to the problem of thermal ignition is outlined. © 1988 The American Physical Society.