A model for the mixing timescale of a turbulent reacting scalar
Abstract
Mapping closure is revisited from the point-of-view of transported PDF (probability density function equation) modeling of initially nonpremixed, turbulent reacting flows. Current ``particle-based'' mixing models in transported PDF methods ignore the influence of chemistry on the dissipation rate of reacting scalar fluctuations. For fast chemistry, this assumption can yield significant errors in estimating the average mixing timescales required by these models (and more sophisticated models which account for an entire spectrum of mixing frequencies). A model for the timescale of reactive scalar mixing in the flamelet regime is developed and comparisons are made with direct numerical simulations. The results show that the relaxation timescale can be significantly reduced due to reaction.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2001
- Bibcode:
- 2001APS..DFD.AB001C