Spectral Line-Based Weighted Sum of Gray Gases (SLW) model was implemented to Computational Fluid Dynamics (CFD) Solver, ANSYS FLUENT. Discrete Ordinate Method (DOM) available in ANSYS FLUENT was used as Radiative Transfer Equation (RTE) Solver. ANSYS FLUENT with SLW was applied to the prediction of incident heat fluxes for three test problems; two containing isothermal homogenous/nonhomogenous water vapor and one isothermal water vapor/carbon dioxide mixture. Predictive accuracy of SLW in ANSYS FLUENT was assessed by benchmarking its predictions against those of ray tracing (RT) with Statistical Narrow-Band (SNB) and Method of Lines (MOL) solutions of DOM with SLW. Comparisons reveal that the results of CFD code are in good agreement with the benchmark solutions. This finding proves that the use of DOM with SLW in CFD codes would provide more accurate solutions in studies involving gas combustion, where accuracy in spectral radiative properties plays dominant role in heat flux predictions.