On the subgrid dissipation concept for large eddy simulation of turbulent combustion

Abstract

A new subgrid turbulent combustion model for LES is derived based on the eddy dissipation concept (EDC). To be consistent with the LES framework, the relationship between the subgrid quantities and the fine structure ones is built from the unresolved part of the energy cascade, hence the subgrid dissipation concept (SDC). The fine structure quantities are directly computed using the subgrid scale ones. Resolving local laminar flame structures is allowed if the grid resolution permits. The model is examined using premixed piloted jet flames and non-premixed swirl flame. Satisfactory predictions from the SDC model are obtained in the test cases, showing improvements with respect to the standard EDC model. The new SDC model is relatively insensitive to the grid resolution.