Direct numerical simulation of turbulent nonpremixed flame extinction by water spray

This paper presents a brief overview of our INCITE 2007 project on the direct numerical simulation of nonpremixed flames subjected to turbulent flows and water spray evaporation. The simulation is a culmination of our recent developments in advanced physical submodels associated with radiative heat transfer and Lagrangian spray dynamics. One of the main objectives is to identify and verify a unified extinction criterion based on the flame weakness factor built on the excess enthalpy variable concept. The results from two-dimensional turbulent ethylene-air flames suggest that the proposed diagnostic tool provides a correct measure of flame weakening. Further work is under way to extend the analysis over a wide range of parametric conditions.