[FLASH-USERS] A question about the Hydro/WindTunnel solver

[Klaus Weide]

On Mon, 28 Mar 2016, Ludmila María Rechiman wrote:

> Dear community of FLASH users and developers,
>                                                                         I
> am new trying to use Hydro libraries of
> FLASH code (/FLASH4.3/source/physics/Hydro/HydroMain/).
> In particular I was able to simulate the WindTunnel example. The default
> size of is -nxb=8 -nyb=8 and the solutions does not seems to capture the
> shokwaves in a sharp manner. 

I suspect that this may be just a matter of your visualization.

For 2D data, you should start with adding a "Pseudocolor" plot in Visit, 
not a "Volume" plot.

> Then I decided to run another simulation using
> -nxb=64 -nyb=64 in order to get a well defined shockwave, but the solution
> is still blurred (I attach a quick view). The AMR mesh seems to have very
> tiny cells to get a good resolution, but by increasing the parameters -nxb
> -nyb up to 64  I can not get better results.

It is generally preferable to leave NXB and NYB smaller (something like 8 
or 16) and just increase lrefine_max to get higher resolution.

Klaus