Reacting flow in an industrial gas turbine combustor: LES and experimental analysis

Abstract

In this investigation the physics of the reacting swirling flow of a commercial industrial gas turbine burner (SGT-100) was researched using combustion Large Eddy Simulation (LES) and experiments. In the experimental studies the flow field, temperature and major species concentrations were measured using Particle Image Velocimetry (PIV), OH Planar Laser-Induced Fluorescence (OH-PLIF), one-dimensional laser Raman scattering and OH chemiluminescence imaging. For the finite-rate chemistry LES, two global and two skeletal reaction mechanisms were utilized to evaluate the accuracy and tradeoffs of global and skeletal reaction mechanisms. This type of assessments has previously been carried out for simple flames but not for industrial flames at laboratory conditions with detailed measurement data. The LES predictions generally show very good agreement with the experimental data for the flow field, temperature and major species. Different reaction mechanisms do not affect the flow field as much as the temperature and species profiles, which show clear imprints of the selected reaction mechanism. The results further indicate that the industrial flame is best captured with the skeletal reaction mechanisms, whilst the global mechanisms predict too compact flames. The results from the skeletal reaction mechanisms are then used in conjunction with the experimental data to assess the flame characteristics which best can be described as interacting flamelets embedded in an environment of distributed reaction zones.