Numerical investigation of the flameless oxidation of natural gas in the IFRF furnace using large eddy simulation Seyed Mahmood Mousavi 1 and Javad Abolfazli-Esfahani* 2 1,2 Center of Excellence on Modeling and Control Systems (CEMCS) & Mechanical Engineering Department, Ferdowsi University of Mashhad, Mashhad 91775-1111, Iran), Abolfazl@um.ac.ir (Submission date: February 24, 2014; Revised Submission date: March 18, 2014; Accepted date: May 11, 2014) ABSTRACT In this paper, in order to investigate the effect of working parameters on 3D non-premixed Flameless oxidation occurring in the IFRF furnace, large eddy simulation model is applied on OpenFOAM environment. The radiation and combustion are modeled by applying the finite volume discrete ordinate model and partially stirred reactor, respectively. Furthermore the detailed mechanism GRI-2.11 is undertaken represent chemistry reactions. The obtained results are compared with the published experimental measurements. After ensuring the accuracy of the LES method, the combustion characteristics are examined with different fuel injection angles, adding H 2 O, H 2 , and the inlet Reynolds number. The results indicated significant changes in the characteristics of the Flameless oxidation process. 1. HEADING The energy production and its consumption have always been one of the human’s main concerns. Nowadays, regarding the restriction of the fossil energy resources and their environmental impacts, the researchers are trying to investigate an appropriate solution for energy saving and the reduction of pollutant emissions. In the recent years, new methodologies are presented for substantial energy savings and dramatic reduction in CO and NO x emissions. One of the approaches is the application of Flameless oxidation (FLOX) technology. FLOX technology was initially developed to minimize NO x emissions produced in industrial furnaces using high temperature preheated air [1]. In FLOX technology, the input temperature of reactants is higher, while the temperature rise during combustion is lower than the self-ignition temperature of the reactant mixture [2]. This new technology is also named “Moderate or Intense Low- oxygen Dilution (MILD)” and “high temperature air combustion (HiTAC)”. International journal of spray and combustion dynamics · Volume · 6 · Number · 4 – pages 387 – 410 387 *Corresponding author email: Abolfazl@um.ac.ir