Experimental and Numerical Study of Flameless Combustion in a Model Gas Turbine Combustor

Abstract

Flameless combustion is an attractive solution to address existing problems of emissions and stability when operating gas turbine combustors. Theoretical, numerical and experimental approaches were used to study the flameless gas turbine combustor. The emissions and combustion stability were measured and the limits of the flameless regime are discussed. Using experimental techniques and Large Eddy Simulation (LES), detailed knowledge of the flow field and the oxidation dynamics was obtained. In particular the relation between the turbulent coherent structures dynamics and the flameless oxidation was highlighted. A model for flameless combustion simulations including detailed chemistry was derived. The theoretical analysis of the flameless combustion provides 2 non-dimensional numbers that define the range of the flameless mode. It was determined that the mixture that is ignited and burnt is composed of ∼ 50% of fresh gases and ∼ 50% vitiated gases.

Keywords:

• Flameless combustion
• Gas turbine
• Large eddy simulation
• PIV
• Tabulated complex chemistry

Acknowledgments

This work was partially financed by the Swedish energy agency STEM within the program “termiska processer för el-produktion.” The simulations were run on HPC2N and LUNARC facilities within the allocation program SNAC.

Notes

*Based on one of the jets.