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

[Konstantin Manukovskiy]

Dear Klaus,

Thanks a lot for your clear answers. I was misled by user's guide which  
states the following 'Grid support for non-Cartesian geometries has been  
newly included in the unsplit hydro and MHD solvers in the current release.  
The supported geometries are (i) 1D spherical (ii) 2D cylindrical in r-z  
and r-theta.' So the last statement is not the case. At least at the moment.

Best regards,
Konstantin.


Klaus Weide writes:

> 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