J Aminian - School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran, IRAN
S Shahhosseini - School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran, IRAN
M Bayat - Research Institute of Petroleum Industry (RIPI), Tehran, IRAN

In this paper, flameless combustion in a lab-scale jet in hot coflow (JHC) burner with 3 and 9% oxygen mass fraction in the oxidizer stream is numerically simulated. A comparison of different turbulence models and kinetic mechanisms is reported based on the Eddy Dissipation Concept (EDC) combustion model. Turbulence was modeled using four variants of the k-ε model including the standard, modified, realizable and RNG together with the Reynolds stress model (RSM). Three different chemical reaction mechanisms including the KEE, DRM-19 and DRM-22 are also compared. Comparison of temperature and mixture fraction profiles between the experimental and predicted values illustrated that for the unconfined, axisymmetric JHC flames reasonable predictions can be obtained employing the modified k-ε model together with KEE chemical kinetic mechanism. For the 3% flame, however, some improvements on the predicted peak flame temperature were achieved using the DRM-19 with more computational cost.

Vitiated coflow, mixing field, MILD combustion, chemical mechanism, turbulence model, CFD