Large eddy simulation of dual-fuel swirl flames

Dual-fuel combustion, where fuels of differing reactivity are injected in the combustor separatelyin time or space, is of interest for various applications. This study numerically investigatesdual-fuel flames using Large Eddy Simulation (LES) with the Doubly-Conditioned MomentClosure (DCMC) model. Specifically, it examines a swirl flame with a liquid fuel sprayof n-heptane (C7H16) in lean premixed methane/air (CH4/air) at premixed equivalence ratios(ϕpmx) of 0.14 and 0.56, spanning values below and above the lower flammability limit (LFL).The influence of ϕpmx on the structure of the flame is analysed in detail in both the physicalspace and the conditional scalar space of DCMC. The results are in reasonable agreement withexperimental data concerning reaction zone location and flame shape. Further work must focuson capturing the extinction conditions