Parametric study of EDC model constants for modelling lifted jet flames in a heated coflow

Abstract

Moderate or Intense Low oxygen Dilution (MILD) combustion offers improved thermal efficiency and a reduction of NOx pollutants and soot emissions compared to conventional combustion. Previously MILD combustion in the Jet in Hot Coflow (JHC) burner, using methane-based fuels, has been simulated with the Eddy Dissipation Concept (EDC) turbulence-chemistry interaction model. In this paper, the EDC model is used with a modified standard k-ε (SKE) turbulence model to simulate an ethylene-nitrogen flame in a hot, 9% O2 coflow. Modifications to the parameters used in the EDC model are investigated and a parametric study of Cτ and Cξ is undertaken. The combination of Cτ=3 and Cξ=1, modified from the default Cτ=0.4082 and Cξ=2.1377 used in the original model, shows better agreement with experimentally measured radial profiles than any previous implementation of the EDC model and replicates the visually lifted properties observed experimentally in this configuration which have not been modelled successfully in the past.