[FLASH-USERS] 2D Spherical and Cartesian Geometry

[Klaus Weide]

On Fri, 23 Sep 2016, Michiel Bustraan wrote:

> Firstly, I've been trying to run a simulation in 2D with a spherical geometry, but a few steps after starting the simulation the code crashes due to a negative dt.
> 
> I set the density and temperature constant in the simulation, and the velocity to 0, so nothing should be happening (just as a test case).
> 
> I'm attaching a plot of the density just before the crash. I'm guessing the problem lies in the grid somewhere, but I have no idea how to fix it.?
> 
> 
> Have any of you encountered something like this before?

Michiel,

It is not so unusual to see some sort of instabilities developing close to 
the axis in 2D spherical coordinates, but FLASH should be able to do 
better than THAT.

Wee need more information to understand what may be going on. To start 
with, are you using the latest release version of FLASH? Which hydro 
solver are you using? What was your setup command?

How have you set the geometry to 2D spherical? How have you set related 
runtime parameters, in particular, ymin, ymax, and all boundary 
conditions?

Klaus