Description of Premixed Turbulent Combustion in a Duct with a Step Using Partially Stirred Reactor Models

Subsonic turbulent combustion of a premixed methane–air mixture in a model duct with a backward step is considered (P. Magre et al., ONERA, 1975–1989). The main physical mechanisms characteristic of combustion in gas turbine systems are reproduced in experiments. A brief review of previous numerical simulations of these experiments is given. New results of numerical studies of stabilized combustion in this setup are described. Several approaches to the description of turbulent combustion using partially stirred reactor (PaSR) models are compared with the quasi-laminar approach. A model with variable turbulent Prandtl and Schmidt numbers is presented, and its influence on the simulation of this flow is considered.