<div dir="ltr"><div class="gmail_extra">Hi,<br><br><div class="gmail_quote">On Sat, Feb 22, 2014 at 6:17 AM, Derek Gaston <span dir="ltr"><<a href="mailto:friedmud@gmail.com" target="_blank">friedmud@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">The phase-field system developed by Michael Tonks (copied on this email) will be part of the open-source release of MOOSE (hopefully by the end of next week). Feel free to contact either myself or Mike for more information while we all wait...<div>
<br></div></div></blockquote><div><br></div><div>Thanks a lot for the offer. I checked out the videos of MOOSE and indeed it seems to be a great tool. However, in my group we prefer to develop our own home-made simulation tools (except for tools like PETSc of course). I know that using simulation tools developed by others saves a lot of work, but by experience I can say that when comes the time to implement new things (new mechanisms, new conditions), which were not planned, it becomes difficult and time consuming since you must spend a lot of time to adapt the tool. Therefore, we adopted the policy to develop our own tools.</div>
<div>Moreover, I already dedicated some time to develop a programming interface (ie collections of C++ classes) for our purpose, which is the diffusion and interaction of many species (thousands).<br></div><div><br></div>
<div>Nevertheless, I am reading the paper about the phase-field model behind MOOSE. Maybe I will use this approach for our problems, still don't know. I don't have experience with phase-field models. BTW, thanks Jed for the link. I could download the paper.</div>
<div><br></div><div>Christophe</div><div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div></div><div>In the meantime you can also check out some of the youtube videos of MOOSE in action (the phase-field system is in use in these videos in the microstructure models):</div>
<div><br></div><div><a href="http://www.youtube.com/watch?v=0oz8FD3H52s" target="_blank">http://www.youtube.com/watch?v=0oz8FD3H52s</a><br>
</div><div><a href="http://www.youtube.com/watch?v=4xTfQxpGAI4" target="_blank">http://www.youtube.com/watch?v=4xTfQxpGAI4</a><br></div><div><a href="http://www.youtube.com/watch?v=V-2VfET8SNw" target="_blank">http://www.youtube.com/watch?v=V-2VfET8SNw</a><span><font color="#888888"><br>
</font></span></div><span><font color="#888888"><div><br></div><div>Derek</div><div><br></div></font></span></div><div><div><div class="gmail_extra"><br><br><div class="gmail_quote">
On Fri, Feb 21, 2014 at 5:33 PM, Jed Brown <span dir="ltr"><<a href="mailto:jed@jedbrown.org" target="_blank">jed@jedbrown.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>Christophe Ortiz <<a href="mailto:christophe.ortiz@ciemat.es" target="_blank">christophe.ortiz@ciemat.es</a>> writes:<br>
<br>
> Hi all,<br>
><br>
> Recently I have implemented a 1D problem of coupled diffusion equations<br>
> using PETSc. I did it using finite differences for diffusion terms and<br>
> F(t,U,U_t) = 0. It works pretty well with ARKIMEX3. I get a nice timestep<br>
> variation and all boundary conditions work well.<br>
><br>
> Now I would like to move to 3D problems to simulate the diffusion and<br>
> interaction of species in a "real material". By real material I mean a<br>
> material made of subregions with internal surfaces where species could<br>
> recombine (means Dirichlet). These subregions are distributed in a<br>
> complicated manner, ie not cartesian. A good picture of this would be a<br>
> polycrystal (see attachment to get an idea). Each crystal has a different<br>
> orientation and the boundary between two small crystals forms an internal<br>
> surface.<br>
><br>
> I have several questions on how to implement this:<br>
><br>
> 1) Since, the problem will not be solved in a cartesian mesh, should I use<br>
> unstructured meshes ? If so, how can this unstructured mesh can be<br>
> generated ( I have no experience with unstructured meshes. I always work in<br>
> 1D).<br>
<br>
</div>Are you intending to mesh the boundaries of the crystals? Will you be<br>
dynamically remeshing? (That is very complicated and expensive in 3D.)<br>
What formulation will you be using for grain boundary evolution?<br>
<br>
I think you should check out phase field models, such as the publication<br>
below. Perhaps check out the paper below. The framework (MOOSE) used<br>
for this publication should be released open source on github next week<br>
(check <a href="https://github.com/idaholab/" target="_blank">https://github.com/idaholab/</a>). I don't know if Marmot, the<br>
phase-field component, will be open source any time soon, but they are<br>
typically happy to collaborate. MOOSE uses PETSc for solvers, but<br>
provides a higher level interface.<br>
<br>
@article{tonks2012object,<br>
title={An object-oriented finite element framework for multiphysics phase field simulations},<br>
author={Tonks, M.R. and Gaston, D. and Millett, P.C. and Andrs, D. and Talbot, P.},<br>
journal={Computational Materials Science},<br>
volume={51},<br>
number={1},<br>
pages={20--29},<br>
year={2012},<br>
publisher={Elsevier}<br>
}<br>
<br>
</blockquote></div><br></div>
</div></div></blockquote></div><br></div></div>