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A turbulent diffusion model of Rayleigh-Taylor mixing.
- Source :
-
Annals of Nuclear Energy . Jun2018, Vol. 116, p290-295. 6p. - Publication Year :
- 2018
-
Abstract
- A simple turbulent diffusion model is described for predicting late term mixing due to Rayleigh-Taylor instability at an interface that initially separates two semi-infinite regions of fluid of different densities. The one-dimensional, transient species conservation equation is combined with an available vertical dispersion equation which relates the turbulent diffusivity to the local density gradient and a characteristic mixing length. The similarity solution of the species conservation equation yields the well-known long time result for the vertical extent of the mixing region and shows that the dimensionless growth constant that appears in the mixing thickness equation is simply a measure of the size of the characteristic mixing length. A simple polynomial relation is derived for the heavy fluid volume fraction profile within the mixing region which is in close agreement with the profile obtained from a previously reported numerical simulation of Rayleigh-Taylor mixing. It is demonstrated how the model can be readily applied to predict Rayleigh-Taylor mixing in a finite fluid region between top and bottom boundaries. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03064549
- Volume :
- 116
- Database :
- Academic Search Index
- Journal :
- Annals of Nuclear Energy
- Publication Type :
- Academic Journal
- Accession number :
- 128803877
- Full Text :
- https://doi.org/10.1016/j.anucene.2018.02.042