Modelling of the subgrid scale wrinkling factor for large eddy simulation of turbulent premixed combustion

Fabien Thiesset (1) , Guillaume Maurice (1) , Fabien Halter (1) , Nicolas Mazellier (2) , Christian Chauveau (1) , Iskender Gökalp (1)

1 ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement
2 PRISME - Laboratoire Pluridisciplinaire de Recherche en Ingénierie des Systèmes, Mécanique et Energétique

We propose a model for assessing the unresolved wrinkling factor in the large eddy simulation of turbulent premixed combustion. It relies essentially on a power-law dependence of the wrinkling factor on the filter size and an original expression for the ‘active’ corrugating strain rate. The latter is written as the turbulent strain multiplied by an efficiency function that accounts for viscous effects and the kinematic constraint of Peters. This yields functional expressions for the fractal dimension and the inner cut-off length scale, the latter being (i) filter-size independent and (ii) consistent with the Damköhler asymptotic behaviours at both large and small Karlovitz numbers. A new expression for the wrinkling factor that incorporates finite Reynolds number effects is further proposed. Finally, the model is successfully assessed on an experimental filtered database.

Mots clés: Large Eddy Simulation; Efficiency function; Flame wrinkling; Strain; Stretch

Domaines: Milieux fluides et réactifs

Fabien Thiesset, Guillaume Maurice, Fabien Halter, Nicolas Mazellier, Christian Chauveau, et al.. Modelling of the subgrid scale wrinkling factor for large eddy simulation of turbulent premixed combustion. Combustion Theory and Modelling, 2016, 20 (3), pp.393 - 409. ⟨10.1080/13647830.2016.1139749⟩. ⟨hal-01660283⟩