We present a robust, fast, and highly-automated Reactor Network model within a single simulation framework in Simcenter STAR-CCM+. An industrial gas turbine combustor operating at 3 bar is numerically investigated using the GRI 3.0 chemical mechanism. A baseline CFD solution with RANS and Flamelet Generated Manifold combustion model was used to create the network of reactors. A number of model variations have been investigated, such as the use of constant pressure vs. perfectly stirred reactors. Two options for the temperature solution are considered, namely temperature mapped from the CFD solution and temperature computed from an equation of state. Different numbers of reactors are investigated to understand the overall sensitivity on the key combustion results. It was found that with appropriate clustering variables, using a few thousand reactors provide a reasonable representation of the species fields. The simulation results are compared with the available experimental data for the combustor. The NOx and CO emissions predictions with the Reactor Network model perform better than the baseline CFD model. The Reactor Network model was about ∼3 orders of magnitude faster than a detailed chemistry CFD of the same combustor.