A GAS TURBINE COMBUSTOR FOR INSTABILITY RESEARCH AND LES VALIDATION: METHODS AND MEAN RESULTS

Abstract

A novel atmospheric swirl stabilized dump combustor to facilitate instability investigations and the acquisition of validation and boundary condition data for large eddy simulation has been investigated when artificially perturbed. Combustor features include the capabilities of imposing pressure perturbations upon the premixed flow, preheating the reactant mixture up to 400°C, and introducing dilution air into the chamber. The combustor design is presented in detail. A fully premixed methane/air mixture of equivalence ratio 0.8 and mass flow of 20 mgs⁻¹ perturbed at 100 Hz, 200 Hz, and 400 Hz was investigated in significant detail and the analysis completed. A full description of the high speed phase locked CH chemiluminescence and stereo particle imaging velocimetry used to characterize the unsteady reacting fields, flow fields, and vortex breakdown is given. The ensemble average results presented reveal changes in flame structure with frequency. These were attributed to the upstream movement of the toroidal vortex ring within the internal recirculation zone.

Keywords:

• Gas turbine instabilities
• High speed diagnostics
• LES validation
• Model combustor
• Stereo particle imaging velocimetry

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/gcst.