Experiments on a rotating-pipe swirl burner

Laser-Doppler measurements of mean velocity components and Reynolds stresses are reported in the near-field of a stable swirling flame of a newly designed natural-gas-fired experimental burner. The swirling motion is generated by the rotating outer pipe of the annular air passage, thus providing well defined inflow conditions which can be easily reproduced in computational and modelling studies. Prior to LDA measurements, burner stability characteristics were determined in terms of gas flow rate and pipe rotation speed. The measurements, corresponding to a stable, short, blue flame regime, show that the flow and combustion are dominated by a distinct, standing toroidal vortex, providing a hot core as source of stabilisation.