Assessment of a Differential Subgrid Stress Model for Large-Eddy Simulations of Turbulent Unconfined Swirling Flames

Swirling flames are widely used in engineering to intensify mixing and stabilize combustion gas turbine power plants industrial burners. induces new instability modes, leading intensification of coherent structures, asymmetric geometry, vortex core precession, flame oscillations. Large-Eddy Simulation (LES) has the capability furnish more accurate reliable results than simulations based on Reynolds-averaged Navier–Stokes equations (RANS). Subgrid-scale models LES need describe backscatter (local transfer kinetic energy from small scales larger scales) that is intensified swirling flames. In this paper, Differential Subgrid Stress Model (DSM), previously developed by authors, assessed using an experimental database Sydney University swirl-stabilized turbulent unconfined non-premixed methane-air flame. Regime without precession simulated numerically DSM Smagorinsky subgrid-scale model. Experimental measurements mean velocity, profiles mass fractions, temperature for comparison with simulation data. The standard model considered basic approach. Differences flow field statistics obtained both analyzed discussed. importance taking into account highlighted.