[FLASH-USERS] refinement problems with FLASH 4.2

[Kevin Olson]

Hi Thomas,

This is due to the fact that the Sink particle test uses only a Jeans criterion based refinement test.  This does nothing to detect shocks and other discontinuities in the flow.  I think you will find that if you turn on the standard FLASH refinement criterion plus the Jeans length criterion, you problem will go away...but at the cost of having many more refinements.

Also, the problem you are running is basically that of a collapsing cloud and the regions where you are seeing large errors probably don't have a large impact on the overall solution you are looking for since those regions probably don't have a very high density.

Hope this helps.

Kevin Olson

On May 21, 2014, at 11:18 AM, Thomas Peters wrote:

> Dear FLASH users,
> 
> I am having some problems with the grid refinement in FLASH 4.2. I have attached some slices of a simulation run with the standard setup SinkRotatingCloudCore. The only thing I modified was to set lrefine_max to a larger number in order to get more refinement levels.
> 
> The attached z-slices show very strong jumps in velz at refinement boundaries, while velx and vely remain smooth. However, velx has jumps in x-slices and vely has jumps in y-slices as well.
> 
> Has anyone seen such a problem before and knows how to get rid of it?
> 
> Thanks for your help,
> Thomas
> 
> <BB_hdf5_plt_cnt_blk_velz0142.png><BB_hdf5_plt_cnt_velx0142.png><BB_hdf5_plt_cnt_vely0142.png><BB_hdf5_plt_cnt_velz0142.png>