Large Eddy Simulation‑Based Turbulent Combustion Models for Reactive Sprays: Recent Advances and Future Challenges

Abstract

Numerical simulations of turbulent reactive sprays are challenging
owing to the presence of multiple timescales and multiphysics
phenomena involving complex turbulence spray and turbulence-chemistry
interactions. In turbulent spray flames, several physical phenomena
such as primary and secondary atomization, droplet dispersion, interparticle
collisions, evaporation, mixing, and combustion occur simultaneously,
and hence it becomes a formidable task to model these complex
interactions. To gain fundamental knowledge and advance current
modeling capabilities, it may be appropriate to aim for progress in individual
modeling of breakup, dispersion, mixing and combustion, which
however cannot be viewed in complete isolation. A brief review of the
development of state-of-the-art turbulent combustion models applicable
to the dilute spray regime is presented. Therefore, complexities associated
with the dense regime, including interparticle collisions as well as
primary and secondary atomization, are not covered. Further, we restrict
ourselves to a brief discussion on large eddy simulation, which has
found applications in both laboratory and industrial applications of turbulent
combustion without a change in phase. The gas phase-based turbulent
combustion models such as flamelet, conditional moment closure
and transported filtered density function methods have been developed
and extensively used for combustion without a phase change. However,
careful adaptation and extension of these models are necessary toward
modeling of turbulent combustion with phase change. This article presents
a review of recent advances and directions of future research on
modeling of turbulent combustion for dilute sprays.