Ra. Baurle et al., ASSUMED JOINT PROBABILITY DENSITY-FUNCTION APPROACH FOR SUPERSONIC TURBULENT COMBUSTION, Journal of propulsion and power, 10(4), 1994, pp. 473-484
In a recent experiment, Cheng et al. used uv spontaneous vibrational R
aman scattering and laser-induced predissociative fluorescence techniq
ues for simultaneous measurements of temperature and concentrations of
O2, H-2, H2O, OH, and N2 (and the rms of their fluctuations) in super
sonic turbulate reacting shear layers. Because present computational t
echniques are not suited for the prediction of all of the above measur
ements, a new approach has been developed and is being used to predict
all relevant flow properties and the rms of their fluctuations (where
appropriate). The approach explores the use of a multivariate Beta PD
F for concentrations. In particular, a version developed by Girimaji t
o model scalar mixing in turbulent flows is employed. Predictions usin
g this model were, in general, satisfactory in regions preceding ignit
ion, but not in regions downstream of ignition. Part of the discrepanc
y is a result of our current inability to relate Favre and time averag
es.