scholarly journals Boussinesq convection in a gaseous spherical shell

2019 ◽  
Vol 82 ◽  
pp. 373-382
Author(s):  
L. Korre ◽  
N. Brummell ◽  
P. Garaud

In this paper, we investigate the dynamics of convection in a spherical shell under the Boussinesq approximation but considering the compressibility which arises from a non zero adiabatic temperature gradient, a relevant quantity for gaseous objects such as stellar or planetary interiors. We find that depth-dependent superiadiabaticity, combined with the use of mixed boundary conditions (fixed flux/fixed temperature), gives rise to unexpected dynamics that were not previously reported.

2021 ◽  
Vol 2094 (2) ◽  
pp. 022035
Author(s):  
Gleb Vodinchar

Abstract The problem of toroidal eigenmodes of free oscillations of a viscous fluid spherical shell is solved under mixed boundary conditions. These conditions are a combination of free surface conditions and solid boundary conditions. Such an artificial combination is used sometimes in the numerical simulation of geodynamo problem. The scheme for calculating the eigenmodes is described. It is shown that the use of mixed conditions leads to the disappearance of the first eigenmode with the smallest eigenvalue. A possible reason for this is the physical incorrectness of the mixed boundary conditions.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Eva Llabrés

Abstract We find the most general solution to Chern-Simons AdS3 gravity in Fefferman-Graham gauge. The connections are equivalent to geometries that have a non-trivial curved boundary, characterized by a 2-dimensional vielbein and a spin connection. We define a variational principle for Dirichlet boundary conditions and find the boundary stress tensor in the Chern-Simons formalism. Using this variational principle as the departure point, we show how to treat other choices of boundary conditions in this formalism, such as, including the mixed boundary conditions corresponding to a $$ T\overline{T} $$ T T ¯ -deformation.


2003 ◽  
Vol 33 (4) ◽  
pp. 860-866 ◽  
Author(s):  
A.C. Aguiar Pinto ◽  
T.M. Britto ◽  
R. Bunchaft ◽  
F. Pascoal ◽  
F.S.S. da Rosa

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