By addressing the need for advanced large eddy simulation capabilities that enable the quantitative prediction of fuelsensitivities on combustion stabilization, ignition and emissions, the objective…

This is a cooperative agreement awarded by the National Aeronautics and Space Administration (NASA) to Stanford University, a renowned private research institution, to develop a fidelity-adaptive large eddy simulation (LES) combustion model. The objective is to enable the quantitative prediction of fuel sensitivities on combustion stabilization, ignition, and emissions for gas turbine combustor configurations. The $1,130,126.51 contract, which does not have a set-aside designation, will validate the model against measurements from the Federal Aviation Administration's (FAA) National Jet Fuels Combustion Program, targeting the high shear spray combustor and the UDRI referee rig. The research aims to improve the understanding of turbulence-chemistry interactions, fuel evaporation, and complex chemical mechanisms to enhance the accuracy of combustion simulations.

By addressing the need for advanced large eddy simulation capabilities that enable the quantitative prediction of fuelsensitivities on combustion stabilization, ignition and emissions, the objective of this research is to develop a fidelity adaptive LES combustion model for the accurate prediction of turbulent combustion processes, involving complex and multi-phase turbulent combustion conditions that are only insufficiently represented by single regime combustion models. The proposed model is formulated to require minimal user input, substantially reducing prior expert knowledge about the combustion model selection and flameconfiguration. Specifically, by using information about a set of combustion models, quantities of interest, and a penalty term to constrain computational cost and desired accuracy, this model selects a local submodel assignment so that the LES solution is described by optimal accuracy and computation cost. The key attributes of this model are the local adaptation of the model fidelity and computational complexity to the underlying flow field specific combustion processes, the control of the model accuracy and description of relevant combustion processes through the selection of error threshold, departure function, and quantity of interest, and the representation of realistic fuel chemistry through detailed and reduced kinetic models. Main research aspects that will be addressed are the consideration of complex and reduced chemical mechanisms for the fuel representation, the description of the turbulence chemistry interaction, and the consistent coupling of the multicomponent fuel evaporation to the reaction chemistry and turbulent combustion submodels.the fidelity adaptive combustion model will be validated by considering gas turbine combustor configurations that are currently examined under the auspice of the FAA njfcp. In particular, we are targeting the area 3 high shear spray combustor and the area 6 udri referee RIG. Through direct comparisons with measurements over a range of operating conditions, LBO, high altitude relight and fuel mixtures, FAA catac fuel classes, LES calculations will be performed to assess the accuracy of the model for the quantitative prediction of fuel sensitivities on flame stabilization, ignition, and pollutant emissions.