Comparisons among various theories for turbulent, reacting, and planar mixing layers
Abstract
Ignition in the planar, turbulent, reacting mixing layer was analyzed via several model approaches and comparisons were made. Both Favre and timeaveraged forms of the equations were employed with various forms of the mixing length theory; k, epsilon theory; and k, omega theory. A coordinate transform was employed to remove the singularity at the mixing layer edge where the turbulent diffusivity goes to zero. An iterative quasilinearized implicit finitedifference scheme was used to solve the governing set of parabolic partial differential equations. The nonreacting limit with temperature and density gradients was fully examined. The major differences between the models and types of averaging were in the predicted spreading parameter. The comparison between theory and data was better for velocity profiles than for density profiles. Additional nonreacting variable density data are needed, particularly for high Reynolds numbers. For reacting flows, two different approaches to the calculation of the ignition length were analyzed. Comparisons among the models indicated significant sensitivity to the form of averaging and the choice of kinetics with a lesser sensitivity to the choice of turbulence modeling.
 Publication:

Combustion in Reactive Systems; 7th International Colloquium on Gasdynamics of Explosions and Reactive Systems
 Pub Date:
 1981
 Bibcode:
 1981crs..proc..211P
 Keywords:

 Combustible Flow;
 Gas Mixtures;
 Ignition;
 Mixing Layers (Fluids);
 Shear Flow;
 Turbulent Flow;
 Turbulent Mixing;
 Computational Fluid Dynamics;
 Density Distribution;
 Finite Difference Theory;
 Iterative Solution;
 KEpsilon Turbulence Model;
 Mixing Length Flow Theory;
 Partial Differential Equations;
 Reynolds Number;
 Turbulent Diffusion;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer