Abstract
Combined measurements of three different radical species and parameters such as acoustic pressure, sound pressure level (SPL) and supply gas pressure are carried out to investigate the flame dynamics in an industrial gas turbine combustor. Extensive studies were conducted under different test conditions. The results demonstrate that the chemiluminescence of CH* and C2* species have strong correlations in all operating conditions, and the two signals are almost in-phase, while OH* species has no strong correlation with both the CH* and C2*. The experimental results have also shown that the CH* and OH* only show strong correlation under specific conditions, for example at high equivalence ratios. Care has to be taken in using the chemiluminescent emission of active CH* and OH* as indicators for unsteady heat release.