Turbulent Combustion Interaction Models for LES Simulations of High Speed Flow

At present, the predictive capability of simulation codes and models used in the conceptual planning and design of high-speed propulsion systems is limited by the ability to describe the complex flow fields inside the combustor, mixing models, detailed chemistry and turbulence-chemistry interactions, and subgrid-closure models. The objective of the proposed work is to develop and validate a high-fidelity LES combustion model based on Flamelet Progress Variable Approach for the accurate prediction of high-speed turbulent combustion. At Cascade, we have a state-of-the-art, fully unstructured, multi-physics LES solver that is currently being used to simulate turbulent combustion in military aircraft engines. Our present efforts are on extending our simulation tool to high-speed turbulent combustion, improve its performance and further validate our approach. In Phase I, a comprehensive program is proposed that consists of (i) an a priori study to evaluate critical model assumption of the flamelet-formulation for reacting jet in high speed-relevant cross-flow conditions and (ii) a posteriori validation and applicability assessment of the LES flamelet-combustion model for supersonic combustion against experimental data. The results of these studies will be leveraged towards model development/assessment, validation of the simulation tool, and improvement of the predictive capabilities of the methodology for high-speed turbulent combustion.