Prediction of self-excited combustion instabilities in a gas turbine combustor using a low order analytical model

Abstract

This study is undertaken to predict the self excited instability in lean premixed gas turbine combustors, which are presently used to reduce NO$_x$ emissions in various industries. This study is divided into two parts. The former part deals with formulating a low order analytical model for single nozzle combustor and the results are validated with experimental data. The agreement of theoretical and experimental results is good. Further sensitivity analysis is done for the instability frequency with variation in inlet temperature, combustor pressure, mean inlet nozzle velocity and equivalence ratio with combustor length as the bifurcation factor. The latter part of the study involves modification of the model to incorporate sensitivity analysis for 2 can combustor with cross talk area. The effect of cross talk area geometry on growth rate and instability frequency is also studied extensively.