NUMERICAL SIMULATION OF NON-PREMIXED LEAN METHANE-AIR TURBULENT COMBUSTION IN A HIGH SWIRL BURNER
Javier Martin, Teresa Parra, Francisco Castro
Session: Wall-bounded flows 2
Session starts: Tuesday 25 August, 15:00
Presentation starts: 16:30
Room: Room I
Javier Martin (Department of Energy Engineering and Fluid Mechanics, University of Valladolid, Valladolid, Spain)
Teresa Parra (Department of Energy Engineering and Fluid Mechanics, University of Valladolid, Valladolid, Spain)
Francisco Castro (Department of Energy Engineering and Fluid Mechanics, University of Valladolid, Valladolid, Spain)
Obtaining high efficiency while keeping low levels of NOx emissions is a problem in burner technology that has attracted a lot of attention recently. A swirling flow in combustion ensures a fixed position of a compact flame. In this paper we present simulations of the reacting flow of a non-premixed lean methane/air mixture confined in a high swirl burner. RANS equations are solved with a finite volume method and a SIMPLE algorithm for pressure-velocity coupling. The mesh is composed of more than one million cells. Turbulence was modeled using a RNG K-epsilon using the swirl-dominated version. A PDF was used to model the combustion.
Local properties of the mixture were calculated based on the temperature and local composition. These calculations were developed with the commercial software ANSYS Fluent. The results obtained from this study show that the Inner Recirculation Zone (IRZ) plays a major role in stabilizing the location of the flame in the shear layer between the IRZ and Outer Recirculation Zone (ORZ). In conclusion, the swirling motion allows a more stable combustion of lean mixtures, reducing the fuel consumption and NOx emissions.