Simulations of spark ignition of a swirling n-heptane spray flame with conditional moment closure

Conditional Moment Closure (CMC) extended to two-phase ∞ows and interfaced with a RANS two-phase ∞ow solver has been used to study the ignition process of an n-heptane spray ∞ame in a ∞ow typical of a liquid-fueled burner. The aim was to investigate the in∞uence of the additional source terms due to the droplet evaporation process in the conditional species and energy equation. The droplet source terms in the mean and variance of the mixture fraction equation were also modelled. For comparison, simulations without droplet source terms in the CMC equations were also carried out. The air velocity fleld and droplet size were compared with experimental data and good agreement was found. The ∞ame expansion process following ignition compared qualitatively with fast-camera images from the experiment and the overall ∞ame shape and speed were captured satisfactorily. Comparisons of conditional temperature at difierent locations in the ∞ow fleld gives further insight on how the additional droplet evaporation source terms afiect the ∞ow fleld.