For details on the benchmark problem look for:
"Numerical simulation of oscillatory convection in low-Pr fluids:
A GAMM Workshop"
(eq. B.Roux), Notes on Numerical Fluid Mechanics, 1990, vol.27.

Governing parameters:   

Grashof number:  

Prandtl number:  

Aspect ratio: 

The stability problems yields:

  • critical Grashof number
  • critical frequence  
  • the most dangerous perturbation

Case with no-slip lower and stress-free upper surface (Ra-Fa case)

Get dependence of the critical Grashof number on the aspect ratio:

Get dependence of the critical frequency number on the aspect ratio:

Get patterns of steady flows and their perturbations at critical Grashof numbers (patterns of the flow - left frames - at the most dangerous perturbarions - right frames - at critical parameters):

Get patterns of oscillatory flows (snapshots of streamlines plotted for equal time intervals 0.1T covering the complete period):

Case with no-slip upper and lower boundaries (Ra-Ra case)

Get example of multiple steady states

Look how knowledge about multplicity helps to fit experimental results

See comparison between results obtained by Galerkin and finite volume methods:

Get dependence of the critical Grashof number on the aspect ratio:

Get dependence of the critical frequency number on the aspect ratio:

Get patterns of steady flows and their perturbations at critical Grashof numbers (patterns of the flow - left frames - at the most dangerous perturbarions - right frames - at critical parameters):

Get animated oscillatory flows:

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