Improved Reaction Mechanisms for Combustion of Jet Fuels in Vitiated Air

ABSTRACT: The demand for increased thrust from gas turbine engines, while simultaneously reducing engine size and weight, has lead to real challenges for the design of robust augmentors and interturbine burners (ITBs). Reactive flow simulations of augmentors and ITBs can be used to speed the design cycle of next-generation turbine engines. However, in order for these simulations to be truly predictive, accurate chemical-kinetic models of JP-5/8 surrogate combustion are needed. Existing models have limited predictive capability, especially at vitiated conditions, due to the scarcity of experimental data and the laborious nature of building models by hand. Even less is known about the combustion of alternative, synthetic jet fuels under these conditions. The proposed effort will use computer-aided mechanism generation to construct detailed chemical-kinetic models for JP-8 surrogate compounds at conditions relevant to augmentors and ITBs. Building kinetic models via computer uses only well-defined algorithms, rate rules, and data sets; the process is less error-prone and more systematic than building models by hand. Phase I will result in a detailed reaction model including rigorous statistical validation testing and uncertainty analysis. Phase II will result in a comprehensive, validated full model and reduced models appropriate for multidimensional CFD. BENEFIT: Accurate chemical-kinetic models for petroleum-derived and alternative jet fuel combustion in vitiated air would speed the development of next-generation augmentors and ITBs. This effort would complement the AFOSR Multi University Research Initiative (MURI) to develop JP-8 surrogate kinetic models at combustor conditions. We would work closely with MURI participants to produce a combined model that is valid for a wide range of conditions. This model could also be used in simulations of military diesel engines, particularly engines using exhaust gas recycle (EGR) for NOx emissions reduction.