[FLASH-USERS] Numerical Effects in Spherical Coordinates

[Klaus Weide]

On Wed, 22 Mar 2017, Michiel Bustraan wrote:

> Dear FLASH Users,
> 
> 
> I've been running 2D simulations of shocks in spherical simulations.
> 
> The initial conditions involve a high density around the origin.
> 
> 
> I had to introduce random temperature fluctuations in the inner region to ensure refinement.

Michiel,

1.)
You should not have to introduce artificial fluctuations in order to 
ensure refinement.  A modified Grid_markRefineDerefine.F90 with an 
appropriated  call to Grid_makeSpecialized added, should take care of that.
See the User's Guide if necessary, and you should be able to find  
examples in existing simulations.

2.)
I suggest some experimentation to find out whether lowering the runtime 
parameter cfl will make the oscillations go away (or suppress them 
significantly).

Klaus