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<font class="content">Hey all!<br>
<br>
So I am using a little bit modified Flash 3.3 to do simulations on
galaxy cluster for my master thesis. We have got a MHD setup using
USM. By now there are two species defined, H and He and the
calculations are done with the assumption of full ionization. So
now my part is to extend the simulation that a partially ionized
gas can be calculated with neutral parts H and He, and ionized
parts H+, He+ and He++. After each time step the ionization of
those particles should be recalculated. My plan has been to modify
the USM solver. I thought of integrating two different densities,
one for the neutral and one for the ionized particles. Then add
source terms to the flow vectors of the USM solver. To get those
source terms I would have to modify EOS equations.<br>
<br>
Even though I did quite some reading about multifluid MHD and
spend quite some time playing with flash and it's source code I
can't get my head around some thing:<br>
<br>
1) I recently stumbled over the Ionization module in flash. But I
am not quite sure if I can use it to do what I want and would not
have to modify the EOS and USM modules, but change the setup of
our simulation. This is because of 2)<br>
<br>
2) I read the PhD thesis from Dongwook Lee describing the Unsplit
scheme for multidimensional MHD and tried to pick apart the USM
source code but I can't really find out how flash handles (multi)
species, density and Ionization in the USM solver. Does USM work
with the Ionization module? If so, can USM handle neutral species
and the partially ionized plasma? Do I just have to implement the
Ionized module in the simulation then?<br>
<br>
Thanks a lot in advance,<br>
Patrick<br>
<br>
PS: Sorry if some questions seem stupid but learning flash can be
really overwhelming!<br>
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