Description of premixed turbulent combustion in a channel with a step using partially stirred reactor models

Subsonic turbulent combustion in a premixed methane–air mixture in a model channel with a backward step is considered (P. Magre et al., ONERA, 1975–1989). The main physical mechanisms characteristic of combustion in gas turbine combustors are reproduced in experiments. A brief overview of previous numerical simulations of these experiments is given. New results from a numerical study of the stabilized combustion regime in this combustor are described. Several partially stirred reactor (PaSR) models for describing turbulent combustion are compared with a quasi-laminar approach. A model of variable turbulent Prandtl and Schmidt numbers is presented, and its influence on the reproduction of this flow in calculations is considered.