Coupling of Combustion Simulation with Atomisation and Filming Models for LES in Swirled Spray Flames

High fidelity spray flame modelling without ad-hoc tuning of the injection parameters is proposed for an Euler-Lagrangian LES description of turbulent combustion in swirled two-phase flow chambers. It is tested in a laboratory burner (SICCA-Spray rig from EM2C), which comprises both a simplex pressure swirl and an airblast atomiser. Relevant phenomena controlling the liquid spray inside the injector including primary and edge atomisation from a pressure swirl and an airblast atomiser respectively, secondary atomisation, evaporation and the formation and dynamics of the liquid film that forms on the inner injector wall are taken into account. Particular attention has been applied to understanding the shape of the droplet diameter probability distribution function and how each atomisation model contributes to it. Results show excellent agreement of the spray statistics measured experimentally with and without combustion. A sensitivity analysis of the model parameters shows that the models are sufficiently insensitive to user chosen parameters, which, together with their relatively low computational cost, make these models ideal candidates for industrial applications.