LES-CMC simulations of a turbulent lifted hydrogen flame in vitiated co-flow

Abstract

Results from a study of turbulent lifted jet flame with conditional moment closure turbulent combustion model are reported. First, a qualitative description of the simulation results is given, by examining the instantaneous resolved species mass fraction fields. The structure of the lifted flame is also assessed by comparing the measured temperature and species mass fraction profiles and the simulation results. The model is able to capture the axial and radial profiles of mixture fraction, temperature and major species. The sensitivity of prediction to boundary conditions is also explored and the lift-off height is found to be very sensitive to the co-flow temperature. Finally, the stabilisation mechanisms, auto-ignition or premixed flame propagation, are addressed. No evidence of premixed flame propagation is found: the diffusion in physical space is negligible for all studied conditions.