LES of pre-vaporized Kerosene Combustion at high Pressures in a single Sector Combustor taking Advantage of the Flamelet generated Manifolds Method

Kurzfassung

This paper summarizes the development of an LES based model for reliable description of combustion in a gas turbine combustion chamber. Combustion is described by means of the flamelet generated manifolds (FGM) method. A Smagorinskymodel with dynamic procedure is applied to determine the subgrid scale stresses. A gradient ansatz model is used to represent the sub-grid scale scalar flux in the mixture fraction and in the reaction progress variable equations. Soot formation and radiation are not considered. In order to evaluate the capability of the model for predicting combustion processes induced by complex real fuels a high pressure single sector combustor (SSC) is investigated. This combustion chamber is fuelled with pre-vaporized kerosene fuel and features very complex unsteady swirling flow and partially premixed combustion properties. The validation of the designed tool along with the prediction analysis is carried out in terms of comparison between experimental data (achieved with a nozzle fired at 0.6 Mpa) and numerical results. This reveals that the proposed LES model is able to capture satisfactorily the flow and combustion properties involving. In particular the flame is predicted to be not always attached to the nozzle. It fluctuates between a lifted and an attached regime. This agrees with experimental findings.