Testing of mixing models for Monte Carlo probability density function simulations -: art. no. 047101

Testing of mixing models widely used for Monte Carlo probability density function simulations of turbulent diffusion flames is performed using the data obtained from direct numerical simulations (DNS) that are specifically designed for the study of local flame extinction and reignition. In particular, the interaction by exchange with the mean (IEM) [J. Villermaux and J. C. Devillon, "Representation de la coalescence et de la redispersion des domaines de segregation dans un fluide per modele d'interaction phenomenologique," in Proceedings of the Second International. Symposia on Chemical Reaction Engineering (ISCRE, Netherlands, 1972), p. B I], the modified Curl [J. Jamcka, W. Kolbe, and W. Kollmann, J. Non-Equilib. Thermodyn. 4, 47 (1979)], and the Euclidean minimum spanning tree (EMST) [S. Subramaniarn and S. B. Pope, Combust. Flame 115, 487 (1998)] mixing, models are tested. The tests are designed to examine the mixing model performance when implemented in both Reynolds-averaged simulations and large-eddy simulations. The exact value of the mixing frequency is taken from the DNS, so that the model performance can be more accurately determined. It is found that, in general, the EMST mixing model yields much better results than the IEM and the modified Curl mixing models. (C) 2005 American Institute of Physics.