Autoignition flame transfer matrix: Analytical model versus large eddy simulations

Modern gas turbines need to fulfil increasingly stringent emission targets on the one hand and exhibit outstanding operational fuel flexibility other. Ansaldo Energia GT26 GT36 turbine models address these requirements by employing a combustion system in which two lean premixed combustors are arranged series. Due high inlet temperatures from first stage, second combustor stage predominantly relies autoignition for flame stabilization. In this paper, response of flames temperature, pressure velocity excitations is investigated. The geometry represented backward-facing step. Based conservation equations an analytical model derived solving linearized Rankine-Hugoniot conditions. This commonly used approach describe relation thermodynamic quantities up- downstream propagation stabilized flame. particular, jump conditions taking into account presence moving discontinuity as well upstream entropy inhomogeneities. unsteady heat release rate modelled linear superposition transfer functions, accounting velocity, pressure, disturbances, respectively. results 3[Formula: see text]3 matrix relating both primitive acoustic variables temperature fluctuations across obtained expression compared large eddy simulations with excellent agreement. A discussion about contribution single terms modelling effort provided, focus flames.