Large eddy simulations of methane oxidation at ultra-wet conditions in a model gas turbine combustor applying detailed chemistry

Abstract

The addition of steam to the combustion process is a promising avenue, in order to reduce harmful emissions and simultaneously increase the efficiency. In contrast to traditional flames where the heat release exhibits a thin flame front, operating under high levels of steam dilution leads to further distributed flames with less steep temperature gradients. It is shown that a non-diluted flame suppresses the occurrence of a helical instability present at isothermal conditions. Injecting high amounts of steam alters the flow field and the helical structure is re-established. This report is dedicated to the simulation of methane flames with high steam contents applying Large Eddy Simulations and detailed chemistry in a model gas turbine combustor. A suitable reaction scheme is identified and is then employed for the simulations of the reacting flow. For the validation of the simulations OH* chemiluminescence recordings and PIV measurements serve as a reference.

Keywords

• steam dilution
• implicit large eddy simulation
• combustion
• detailed chemistry
• coherent structures