A Compressible Pressure-based Solution Algorithm for Gas Turbine Combustion Chambers Using the PDF/FGM Model

The investigation of the complex flow interactions occurring between combustion chamber outflow and turbine nozzle guiding vanes in gas turbines has been the subject of numerous studies in the last decade. In common modeling practice, combustion chamber and high-pressure turbine are considered independently from one another, however fundamental experimental evidence shows that outflow conditions sensibly affect swirling flows in simplified geometries. The objective of this study is to propose a novel methodology to pursue the integrated, contextual simulation of the combustor and the first nozzle guiding vane of a jet engine, which can be usefully and efficiently employed also within design procedures. The mathematical model and the solution method, based on the SIMPLE approach, are illustrated, with particular emphasis on the coupling strategy with the PDF/FGM combustion model, initially developed under the assumption of incompressible, low-speed flow. The method has been applied to investigate both academic and complex configurations of industrial interest with excellent results. The detailed description of the innovative investigation tool presented in this paper provides useful insight in physical and numerical issues of great practical relevance.