Large-Eddy Simulation of Reacting Turbulent Flows in Complex Geometries

Abstract

Large-eddy simulation (LES) has traditionally been restricted to fairly simple geometries. This paper discusses LES of reacting flows in geometries as complex as commercial gas turbine engine combustors. The incompressible algorithm developed by Mahesh et al. (J. Comput. Phys., 2004, 197, 215–240) is extended to the zero Mach number equations with heat release. Chemical reactions are modeled using the flamelet/progress variable approach of Pierce and Moin (J. Fluid Mech., 2004, 504, 73–97). The simulations are validated against experiment for methane-air combustion in a coaxial geometry, and jet-A surrogate/air combustion in a gas-turbine combustor geometry.

Burning syngas in a high swirl burner: Effects of fuel composition

“…State-of-the-art numerical computations have been reported in literature which demonstrates the ability of LES to capture the unsteady flow field in complex swirl configurations including multiphase flows and combustion processes such as gas turbine combustion, internal combustion engines, industrial furnaces and liquid-fueled rocket propulsion [18][19][20]. Other investigations including validation of LES calculations for a model gas turbine combustor [21] and more complex General Electric aircraft engines and Pratt and Whitney gas turbine combustors were also reported [22][23]. More investigations on other important aspects of LES based combustion calculations such as effect complex mesh resolution [24] and ignitability characteristics [25] for gas turbine combustion were also carried out.…”

Joint experimental and numerical study of the influence of flame holder temperature on the stabilization of a laminar methane flame on a cylinder

“…In the field of simulation, most models [7][8][9][10][11] assume adiabatic flows. For premixed flames, the famous BML (Bray Moss Libby) approach, for example, which is the workhorse of many theories for turbulent premixed flames [12,13] assumes that a single variable (the progress variable c ) is sufficient to describe the flow: this is true only when the flow is adiabatic.…”

Large eddy simulation applications in gas turbines

“…Despite these additional modelling assumptions required and the complexity of the flow to be represented, LES has already been demonstrated to give good representations of the flow in real combustion systems as shown by, for example, Kim et al (1999), di Mare et al (2004, Kim & Syed (2004), Mahesh et al (2006) and Gicquel et al (2008). In all of these cases LES was shown to capture the dominant flow features well.…”