In this work, results of comprehensive high-pressure tests and numerical simulations of high momentum jet flames in an optically accessible combustion chamber are presented. A generic single nozzle burner was designed as a full-scale representation of one duct of a high temperature FLOX® gas turbine combustor with a model pilot burner supporting the main nozzle. As an advanced step of the FLOX® gas turbine combustor development process, tests and simulations of the entire burner system (consisting of a multi nozzle main stage plus a pilot stage) are complemented with this work on an unscaled single nozzle combustor, thus supporting the development and testing of sub concepts and components like the mixing section and dual-fuel injectors. These injectors incorporate a gaseous fuel stage and a spray atomizer for liquid fuels, both separately exchangeable for testing of different fuel placement concepts. The combustor was successfully operated at gas turbine relevant conditions with natural gas including a variation of the Wobbe index, and with light heating oil with and without water admixture. The presented work is the first of two contributions and covers the description of the experimental setup, an overview of the numerical methods, high-pressure test results for different fuels and variations of the operating conditions including exhaust gas measurements and basic optical diagnostic methods, together with CFD results for several cases. The other part will present detailed and focused investigations of few conditions by complex and extensive optical and laser combustion diagnostics.

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Thermo-acoustic instabilities in gas turbine engines are studied to avoid engine failure. Compared to the engines with annular combustors, the can-annular combustor design should be less vulnerable to acoustic burner-to-burner interaction, since the burners are acoustically coupled only by the turbine stator stage and the plenum. However, non-negligible cross-talk between neighboring cans has been observed in measurements in such machines. This study is focused on the analysis of the acoustic interaction between the cans. Simplified two-dimensional (2D) and threedimensional (3D) equivalent systems representing the corresponding engine alike turbine design are investigated. Thermo-acoustic instabilities are reproduced using a forced response approach. Compressible large eddy simulation based on the open source computational fluid dynamics OpenFOAM framework is used applying accurate boundary conditions for the flow and the acoustics. A study of the reflection coefficient and of the transfer function between the cans has been performed. Comparisons between 2D and 3D equivalent configurations have been evaluated.

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The continuous interest in reducing pollutions and developing both an efficient and clean combustion system require large attention in the design requirements, especially when related to industrial gas turbine application. Although in recent years the advancements in modelling have increased dramatically, combustion still needs a huge computational effort. The Flamelet-Generated Manifolds (FGM) method is considered a suitable solution with an accuracy that can be comparable with detailed chemistry simulations results. The full combustion system can be described by few controlling variables while the chemical details are stored in a database (manifold) as function of controlling variables. Transport equations are solved for the Navier-Stokes system and the controlling variables. The detailed chemistry code Chem1D is used to create the manifolds. Turbulence can be modeled using a PDF approach for the subgrid modeling of the chemistry terms. The OpenFOAM open source CFD package is used as CFD tool for the simulations. The aim of this work is to demonstrate the usage of FGM with OpenFOAM and figure out the status of the implementation. To achieve this goal, the work employs as test case a confined lean jet flame is used. For the case presented, an extensive experimental data set exist, including PIV and Raman data. Results are further compared with traditional methods, while FGM method might be easily extended to other scenarios.

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