[FLASH-USERS] 2D cylindrical geometry using FLASH4.2.2 unsplit solver

[Klaus Weide]

On Fri, 17 Apr 2015, Konstantin Manukovskiy wrote:

> Hi everyone,
> 
> I'm trying to simulate 2D case with non-cartesian grid using unsplit hydro
> solver. According to user guide (Non-Cartesian Grid Support) now it is
> possible to use unsplit solver with 2D cylindrical r-theta geometry. Table 8.7
> describes grid implementations. As far as understand to use 2D cylindrical
> r-theta geometry (with omitted dimension z) I have to specify 'polar'
> geometry. 

Konstantin,

That is correct. (2D 'cylindrical' would mean r-z, with omitted theta.)

> But when I try to run simulation I obtain abort message 'Error
> message is [Hydro_init]: Spherical coordinates are not supported in the
> unsplit solvers'.

Unfortunately, we currently do not support 'polar' geometry in the unsplit 
Hydro solver.

If you just modify the code in Hydro_init.F90 to skip the error message 
and abort for this case, you may or may not get something that works; or 
you might get a hydro solve that appears to work (at least for a while) 
but gives wrong results. So I would not recommend it unless you are really 
determined and willing to understand and modify the Hydro code in various 
places.

The 'polar' geometry SHOULD still work with the split Hydro (PPM) solver.

Klaus