Abstract: In this paper, we simulated numerically the non-premixed combustion provided by two coaxial methane-propane/air jets in a cylindrical combustion chamber. Using CFD Fluent commercial calculation software. In order to find the aero-thermo-chemical characteristics in the burner: temperature, axial velocity and mass fraction of carbon monoxide CO. To study this kind of phenomenon, we used a special treatment of the mathematical model and we chose two models of computation large eddy simulation (LES) and the probability density function (PDF). The objective of this work is to reduce the emission of carbon monoxide CO, and what is considered a gas toxic to the environment. The results obtained give the fuel of methane reduces the carbon monoxide in the products of combustion.

Key words: Models LES and PDF; Combustion Chamber; Methane; Propane; Numerical Simulation CFD.