Cellular convection in a stratified atmosphere
Abstract
The properties of thermal convection in an atmosphere spanning several density scale heights are examined. Both the conductivity and the shear viscosity are assumed to be constant. The anelastic approximation is used, together with a modal expansion procedure in the horizontal directions; this expansion is severely truncated, keeping one or two modes. Only steady solutions are built, for Rayleigh numbers up to 100,000 times critical and Prandtl numbers of 1, 0.01 and 0.0001. The most striking properties of the solutions is that they display an inversion of the buoyancy force in the upper part of the domain, and that the pressure fluctuations play an essential role in controlling the dynamics. Both the effects are ignored in the current mixing-length approach.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1980
- Bibcode:
- 1980A&A....87..315M
- Keywords:
-
- Astrophysics;
- Atmospheric Stratification;
- Fluid Dynamics;
- Free Convection;
- Stellar Atmospheres;
- Atmospheric Models;
- Boussinesq Approximation;
- Buoyancy;
- Flow Equations;
- Nusselt Number;
- Prandtl Number;
- Rayleigh Number;
- Astrophysics