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Experimental measurements are carried out on a non-premixed model combustor, equipped with a double-swirled syngas burner. Mixtures of H 2 , CO, and CO 2 with appropriate contents are used to simulate corresponding syngas used in a practical gas turbine combustor. Planar laser-induced fluorescence (PLIF) of OH radical measurement is adopted to identify main reaction zones and burnt gas regions as well. Together with the temperature and emission measurements during the exhaust section, some important characteristics of the syngas flame are investigated overall. In this paper, the effects of the N 2 dilution and CO/H 2 molar ratio consisting of syngas fuel are investigated. Experimental results show that the syngas flame root near the burner exit demonstrates a double flame front structure. The increase of the CO/H 2 ratio alters the shape and position of the flame root and compresses the main reaction zone. The existence of N 2 diluents, however, changes the whole flame root structure and merges into a single flame root. The CO emission can be controlled to a desirable level for the case of a high CO/H 2 ratio if the flow field is well-organized.

The objective of the current work is to shed light on simulating the flow features of nonpremixed flame stabilized by a circular-disk bluff-body with large eddy simulation technique. Two subgrid scale (SGS) models (Smagorinsky and Germano), combined with a constrained chemical equilibrium model, are applied to simulate this turbulent flame. Validation is made through the particle image velocimetry measurements. The comparison between the numerical simulation and experimental data shows that both models perform well and reproduce most of the significant features of the bluff-body flame, while the Germano SGS model performs better in prediction of turbulent fluctuations. These investigations show that it is possible to describe such flows with relatively simple turbulence and combustion models with moderate grids.