The continuity of evolving pollutant emission regulations requires the design and the development of new burners. The separated-jets burner concept is an example that implies a careful understanding of the turbulent oxy-fuel flames properties developing in a furnace. Modeling, such as turbulent combustion, is a challenge, as it combines complex flow and transport phenomena with combustion events including a vast amount of species and reactions. The flamelet generated manifold (FGM) method is a promising technique to model reacting flows using a tabulated chemistry approach. It is considered as a function of the mixture fraction (Z) and a reaction progress variable (Y). In this work, the interaction of three aligned separated jets is numerically investigated. The central jet provides the natural gas and the others side jets provide the pure oxygen. Turbulence is modeled using the large eddy simulation model in which the dynamic Germano approach is applied to determinate the sub-grid scale stress. In the reacting case, the turbulence chemistry interaction is achieved by coupling the FGM tabulated chemistry within the computational fluid dynamic code. The numerical results show a good agreement with experimental data notably in the isothermal case. In the reacting case, statistical flow field quantities for velocity, mixture fraction, and temperature are analyzed in detail.