CFD analysis of turbulent reacting flows within practical combustors and high pressure nozzle guide vane passages
Rolls-Royce Plc Civil Aerospace business is a major manufacturer of aero engines and in order to stay competitive within the growing aerospace market continuous research and development are an absolute necessity. With increasing combustion temperature and emissions regulations the Combustor-Turbine Interaction (CTI) becomes more and more important. A lot of research in this field is already done and has shown that CTI is significant and important to account for. Increased computational power nowadays makes it possible to validate the capability of combustion CFD to model this CTI for practical combustors at Rolls-Royce Plc.
This thesis demonstrates that combustion CFD is capable of modelling turbulent reacting flows within single sector geometry of a combined practical combustor and high pressure nozzle guide vane (HPNGV) passages using simulation models for industrial applications. Steady-state RANS simulations with a realizable k-epsilon turbulence model and equilibrium chemistry model have shown to give reasonable predictions regarding near wall gas temperature distributions for two geometries. Furthermore the intended difference in flow field features for both geometries is captured in terms of flatness of the combustor exit temperature distribution. HPNGV performance predictions are given containing radial HPNGV inlet and outlet profiles and axial pressure loss. The predictions have furthermore shown that the presence of the HPNGVs has an impact upstream in the combustor known as the blockage effect. At a plane upstream at approximately 1.5 chord length of the HPNGVs this blockage effect is negligible, which makes this plane suitable for the development of a detailed back-end model of the combustor with HPNGVs and probe for further CTI research.