Assessment of tabulated chemistry models for the les of a model aero-engine combustor

Tabulated chemistry methods present a compromise between computational cost and the ability to capture complex combustion physics in high-fidelity numerical simulations. The application of such models entails a number of modeling decisions, that may affect the simulation results significantly, especially in partially premixed combustion, where the assumption of the existence of underlying premixed or non-premixed flamelet structures is arguable. In this work, different classical tabulation strategies are assessed in terms of their ability to predict the lift-off induced by localized extinction in a model aero-engine combustion chamber: the Cambridge swirl spray flame. The lift-off dynamics of the stable n-heptane spray flame are compared using: i) premixed flamelets, ii) stable and unstable counterflow diffusion flamelets, iii) stable and unsteady extinguishing counterflow diffusion flamelets, iv) unsteady extinguishing and reigniting counterflow diffusion flamelets at a given strain rate. The extinction and reignition events associated to the lift-off are validated against OH-PLIF measurements, and the temporal evolution of the lift-off and reattachment is analyzed.The research leading to these results has received funding from the European Union’s Horizon 2020 Programme under the CoEC project, grant agreement No. 952181 and the Clean Sky 2 Joint Undertaking ESTiMatE project under grant agreement No 821418.Peer ReviewedPostprint (published version