The UTC Graduate School is pleased to announce that Robert Smith will present Master's research titled, Characteristics of flame-turbulence interactions in freely propagating turbulent premixed flames under decaying and forced isotropic turbulence conditions on 11/10/2025 at 3:30pm in ECS 426. Everyone is invited to attend. 

Engineering

Chair: Dr. Reetesh Ranjan

Abstract:

Turbulent premixed flames are observed in energy conversion and propulsion applications. The flame-turbulence interactions within such flames are characterized by highly nonlinear, unsteady, and multiscale processes, which directly contribute to the challenging nature of their investigation. While the turbulence affects the flame surface by stretching and straining it, the heat release by the flame affects the turbulence characteristics. Previous numerical studies of freely propagating flames have utilized either forced or decaying background isotropic turbulence to provide detailed insights into the characteristics of flame-turbulence interactions; however, none of the studies have made direct comparisons with cases where the turbulence decays or is sustained using a forcing strategy. This study compares the instantaneous and statistical features of turbulent premixed flames via direct numerical simulations by considering both decaying and forced turbulence scenarios. Four conditions are considered by varying the initial length-scale and velocity-scale ratios characterizing such flames that correspond to the thin reaction zone (TRZ) and broken/distributed reaction zone (B/DRZ) regimes. A comprehensive comparison of decaying and forced turbulence scenarios under four conditions is performed in terms of instantaneous reacting flow field, average flame structure in both physical and state-space, and enstrophy transport.