Large eddy simulation of dilute acetone spray flames using CMC coupled with tabulated chemistry

Abstract

A conditional moment closure (CMC) method has been coupled to a large eddy simulation (LES) for the modelling of turbulent spray flames. The present study presents an extension to CMC (CMCe) that remediates some inconsistencies of an earlier LES–CMC study (Ukai et al., 2013) [1]. Here, the CMC approach is coupled with a chemistry table that allows for spatial and temporal variations of the tabulated chemical composition and ensures a reasonably accurate computation of the chemical source term of the LES-filtered reaction progress variable despite large fluctuations around the conditional means computed by the CMC equation. CMCe is validated by comparison with experimental results of two dilute acetone spray flames with pre-evaporation. Temperature predictions and axial spray velocities are markedly improved, especially along the centreline, while the velocity RMS shows reasonable agreement.