In this study, a sensitivity analysis based on Reynolds Averaged Navier-Stokes (RANS) equations has been conducted to model the reacting turbulent flow in a swirler used in a (Disk-Oriented) gas-turbine using propane-air mixture. Several popular turbulence models and combustion models have been compared at different equivalence ratios. The effects of simulation parameters such as turbulence intensity, TKE Prandtl number, Schmidt number, and gravity direction have been studied. The contour plots of the species mass fraction (H2, OH) and temperature distributions from the CFD results are compared against the experimental visual results. The results showed that the realizable k-ε model and the steady diffusion flamelet model (SDF) are more suitable to model the turbulence combustion in the swirl domain. The computations further showed that the TKE Prandtl number and gravity are sensitive parameters to model the combustion from the swirler, while the Schmidt number and turbulence intensity showed less sensitivity.