The k-epsilon model of turbulence was modified to allow for the effect of damping of turbulence by a positive radial density gradient in swirling flow. The inclusion of density fluctuations in the basic conservation equations yielded a modified set of equations for kinetic energy and dissipation of turbulence. The analysis confirms that in density-stratified swirl flow, the ratio of damping of turbulent kinetic energy by density stratification to its generation due to shear stress can be expressed in terms of a dimensionless group, the Modified Richardson number recommended for the characterization of such flows. New equations were used to modify the FLUENT 4.51 source code. Results of CFD calculations made with and without the modified turbulence model were compared with experimental data previously obtained on a ducted turbulent methane diffusion flame in swirling annular air flow. Agreement between experiment and computations greatly improved when the modified turbulence model was used.