[esp-r] Open Source Software

[Jake Zwart]

Hi all,

I have just finished a project where I needed to perform FEA analysis.  I
ended up installing CAElinux as a dual boot option on my notebook, and using
Salome-Meca, an open source product that has an FEA solver competitive with
the higher end commercial programs along with a decent GUI base pre/post
processor.

I have used esp-r for performing simulations on my own home.  I have not
used it for commercial or research purposes.  So I have some but not
extensive knowledge of the program, but have followed the comments on this
list.  The comments from a few years ago regarding the long term development
of esp-r leads to this posting.

Salome is a geometry creator and incorporates meshing tools.  It contains
all the primitives of points, lines wires, faces, shells and solids.  A
building, or a room could be considered a shell.  For the purposes of FEA or
CFD computations, the program has a built in interface to meshers, and can
also accept commercial meshers.  It is interfaced with Code-Aster to perform
the FEA calculations.  Finally it will post-process the results.  

The interface is a modern look and feel graphical user interface.  All the
commands that are used to build a geometrical structure are saved as a
python script. Salome can dump the python script, which can be edited and
then loaded again, for recalculation.

Code-Aster, the FEA portion of the program, is actually a number of Fortran
or C coded modules that are strung together in a python script.  This makes
the program extremely modular, and one area can be changed without affecting
any of the other modules.  Python stores the information output from each
module for the next module to use.

I have not used Code-Saturne (CFD program), but from what I can determine it
uses python scripting similar to Code-Aster to control it.  Then there is
another program called SYTHRES, about which I don't know much.

The programs are all open source, and are also compatible with a number of
other open source programs such as GMSH, for geometry and mesh creation and
Paraview, a well developed US government open post-processor.  The FEA and
CFD portions are actively developed by EDF the research arm of the French
nuclear industry.  I believe Salome, the pre/post processor is also
supported partially by the EDF team.

There are both similarities and differences in the CFD/FEA world, compared
to building envelope/plant simulation world.  Both require geometry input
and post processing.  esp-r uses results from FEA analysis to give more
accurate foundation heat loss results.  esp-r has a simple CFD module.

Based on the comments from a few years ago, where there seemed to be
interest in modernizing the programming and development environment of
esp-r, and then learning about the above open source programs, it seemed
that there might be synergy.  I expect it would require looking at the core
computational engine of esp-r, breaking it out into individual blocks, and
have each block called by a python script.  The current esp-r user interface
can be maintained and/or ways sought to make Salome or other open source
software work well for the pre-processing (building geometrical layout)
stage.  

In this environment there would be options to use highly developed CFD and
FEA code, chained together with building simulation code, to perform
analysis that includes airflow in rooms and 3D heat transfer between the
building or plant elements and the ground.  

I thought I would throw the concept out to see if there is any interest in
discussing a building simulation program that is run from within a python
script, and the flexiblity that it would allow, in a manner that would
leverage existing open source tools to provide options in the CFD/FEA
domains.  

Jake Zwart