Hi Daniel,
thank you so very much for your quick and rather encouraging response.
Let me follow up with more questions then.
1) Can FiPy handle curvature effects, such as capillary rise in a
tube, or surface tension driven species segregation?
2) So far, I have thought of the Level Set method as an alternative to
the Phase Field method. Is this an incorrect view, and which of the
two is the better method to use?
3) When I refer to species diffusion, I have only one species to
account for. Will that by itself mean a substantial speed decrease
over problems that use Navier-Stokes and heat conduction only?
4) How would you describe the development status of FiPy? What
direction is it going into? Are all features presently implemented in
the code documented? Are there more features implemented than
documented? Are there fewer features implemented than documented? Does
all that IS documented work properly? Is there a development roadmap
for FiPy?
I apologize for so many questions, but I come to FiPy from an odyssey
through the free PDE software world, including OpenFOAM, FreeFEM,
keyFE2 and GetDP. While each have great features by themselves, they
either lack the flexibility or the usability to implement the problem
I described. I just want to make sure that I have a fighting chance
with FiPy. There are several pieces of commercial software out there,
or course, that could handle this, but they all go for between $10,000
and $20,000, which is completely out of the question.
Thanks,
Matt Koch
----- Message from [EMAIL PROTECTED] ---------
Date: Mon, 16 Apr 2007 16:13:34 -0400 (EDT)
From: Daniel Wheeler <[EMAIL PROTECTED]>
Reply-To: [email protected]
Subject: Re: ... FiPy capabilities ...
To: Multiple recipients of list <[email protected]>
Hi Matt,
On Apr 16, 2007, at 3:01 PM, Matt Koch wrote:
Hello,
I was just wondering whether FiPy, in general, can solve a set of
PDEs including the following equations:
1) Navier-Stokes equation (transient, non-linear)
2) Heat Conduction (transient, non-linear, with phase change)
3) Species Diffusion (transient, non-linear, with phase change)
Yes to all the above. I am currently using fipy to solve a phase field
binary solid-liquid-vapor problem with full
Navier-Stokes. Examples for this problem will be publicly available in
the next month or two.
The boundary conditions would be as follows:
1) moving interface of liquid to gas, constant inflow
Should be okay, but I haven't tried it.
2) moving interface of liquid to solid, Stefan Problem, thermal radiation
3) moving interface of liquid to solid, equivalent Stefan Problem
for species
Yes to the last two. I think the above are generally introduced source
terms that are applied to the "interface region" of the domain.
They would be implicitly handled with a phase field method, but would
require explicit construction for
the level set method. Note, that these are different from boundary
conditions in fipy that are applied to the external mesh.
I am not after exact examples or implementations, just a general
statement as to whether it might be possible to attack such a
problem successfully in FiPy at all?
Yes with caveats. fipy has efficiency limitations that we have only
partially addressed and no parallel as yet. Flow problems
with multiple species take a lot of memory and converge slowly so this
is definitely a consideration. I am solving my flow
problems in 2D with success (but not fast).
I am thinking, though, of capturing the liquid to solid interface
and the liquid to gas interface with two separate Level Sets?
I have never used the level set method in fipy with flow, I have used
it exclusively for electrodeposition problems. I may be
working with Andrew Reeve later this summer who is interested in
ground water flows on addressing some of the level set
and flow issues. The level set code as it stands only works on 1D and
2D grids and may need some tweaking for new
problems. Also, it is written entirely in python.
Hope this helps.
Cheers
Thanks and Regards,
Matt Koch
--
Daniel Wheeler
----- End message from [EMAIL PROTECTED] -----
