On a new, one-dimensional, time-dependent model for turbulence and convection. I - A basic discussion of the mathematical model. II - an elementary comparison of the old and the new model
Abstract
In the novel model presented for turbulence and convection in regimes with very large Reynolds numbers, all Reynolds correlations are consistently modelled by means of a diffusion approximation. Model equations are considered for spherical symmetry, and the general properties of the turbulence equation are characterized with attention to the equation's consistency within the framework of the equations. The concepts of overshooting, semiconvection, and convective instability are straightforwardly interpreted within the model. In the second part of this work, it is noted that the new formulation features characteristic time-scales for igniting and decaying turbulent motions, while the Stellingwerf (1982) lacks an intrinsic time-scale for the growth of turbulence.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1992
- Bibcode:
- 1992A&A...253...92G
- Keywords:
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- Convection;
- Energy Transfer;
- Hydrodynamic Equations;
- Mathematical Models;
- Stellar Structure;
- Turbulence Models;
- Approximation;
- Radiative Transfer;
- Spatial Distribution;
- Temporal Distribution;
- Astrophysics