Scalar variance transport in the turbulence modeling of propulsive jets

A variable turbulent Prandtl number model is applied to the prediction of l aboratory jets with significant temperature variations. The model involves solving supplemental scalar equations for the temperature variance and its dissipation rate along with the k-epsilon equations. The model is also appl ied to jets with variable composition with the aim of building a consolidat ed approach to model fluctuations of both temperature and species mass frac tion. Comparisons are presented for subsonic jets for which scalar fluctuat ion measurements are available. The same coefficients are used for temperat ure/species variance and dissipation rate equations. Excellent agreement wi th data is obtained for round jets with respect to scalar fluctuation inten sities and prediction of turbulent Prandt/Schmidt numbers.