Thermo-Acoustic Analysis of an Advanced Lean Injection System in a Tubular Combustor Configuration

A. Giusti[1], A. Andreini[1], B. Facchini[1], F. Turrini[2], Ignazio Vitale[2]
[1]Department of Energy Engineering, University of Florence, Florence, Italy
[2]Avio, Turin, Italy

In this work a thermoacoustic analysis of a tubular combustor with an advanced lean injection system is presented. The performed analysis is based on the resolution of the eigenvalue problem related to an inhomogeneous wave equation which includes a source term representing heat release fluctuations (the so called Flame-Transfer-Function, FTF) in the flame region. The effect of the mean flow is neglected whereas the effect of temperature variations on pressure waves is included by considering the temperature profile in the combustion chamber obtained from CFD (Computational-Fluid-Dynamics) computations. Comparisons with available experimental data showed the necessity of an improved FTF, more suitable for liquid fueled gas turbines where the evaporation process could play an important role in flame heat release fluctuations.