In order to predict the stability limits of a model gas turbine combustion chamber, a non-adiabatic presumed-pdf reaction model applying a global chemical kinetics scheme has been developed. Radiative heat loss in the combustor has been taken into account by means of the Monte Carlo Method. The investigations are carried out for aerodynamically stabilised flames under high turbulence and lean mixture conditions applying modern airblast nozzles. Such applications cover a wide range of operation conditions where stable combustion has to be guaranteed. Therefore, a growing demand exists for the knowledge of lean blow out limits, which is an important design parameter for the dimensioning of combustor airflows. The reaction kinetic of the combustion process is influenced by the state of mixing as well as by the temperature distribution in the flow field. Hence, to consider the influence of the temperature distribution on the chemical reaction process in turbulent flames, in terms of the spatial temperature distribution and temperature fluctuations is essential for flame stability. The claim for numerical models to predict stability, thus, is very challenging. In contrast to many stability models which mainly are based on global quantities, numerical models using local quantities offer the highest possible flexibility concerning variation of examined geometry and operating conditions. In case of confined diffusive swirl-flames, the consideration heat transfer processes is crucial but, the exclusive consideration of convec-tive heat transport has proven to be unsuitable. Thus, for an adequate prediction of the temperature distribution in a combustor and on the combustor walls, respectively, both phenomena have to be accounted for. Both of these processes, heat release and heat transfer, are described by statistical approaches in this work due to the high accuracy that can be achieved by these model types.
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