ASSUMED AND EVOLUTION PROBABILITY DENSITY-FUNCTIONS IN SUPERSONIC TURBULENT COMBUSTION CALCULATIONS

The objective of this investigation is to compare the use of assumed probability density function (PDF) approaches for modeling supersonic turbulent reacting flowfields with the more elaborate approach where the PDF evolution equation is solved, previous calculations using assumed PDFs have shown modest improvements in the prediction of mean flow variables when compared with experimental data, However, these PDFs were unable to predict the higher order correlations with any reasonable degree of accuracy. Solving the evolution equation for the PDF did show slight improvements in these correlations when compared with experiment, but at a substantial cost in computer storage and time, Both approaches yielded comparable mean now quantities.