Computer Programs Related to Extrusion Science and Engineering
There a quite a number of tools that can be helpful to
the science and engineering related to extrusion. In general,
there is quite a gap between food extrusion practice and what is
possible. Food extrusion practice tends to include
mental visualization, pencil and paper calculations, maybe
spreadsheet calculations, perhaps some simple CAD. At this point,
what is possible includes CAD programs that can render parts in 3
dimensions and simulation programs limited by the type of data you can
get to feed into the programs. This page
is intended to help get the reader from where they are to the level
they may want to reach. In keeping with the intent that any
person should be able to access the software without the need to
spend a great deal of money, this page will focus on opensource
software. Since this tends to be most readily available on
Linux (an opensource and free operating system), this page will focus
on the software available for Linux. However, most, if not all
of the software will be available for Windows and perhaps Macintosh.
There are choices available. Windows, McIntosh, Linux, and Unix are the widest spread ones. There are sure to be programs available for the various operating systems. The author of this site is a fan of opensource programs, so Linux is the OS that will be discussed. A wide variety of Linux distributions are available, and a wide range of tools are available on them.
There is a linux distribution called CAELinux that was designed to be focused on engineering tools. See the bottom of this page for a little information on that distribution.
A program that can serve as a CAD program is always a good place to start for engineering tools. One program that can serve partial functions of CAD is Salome Meca. In reality, Salome Meca is a Pre- and Post-Processing tool for numerical analysis, but the tools that allow the creation of pieces and volumes that can work acceptably as a CAD program. Eventually, some 3-D pieces will be displayed below to give an idea of what a Salome Meca can do even with little knowledge or training.
Salome Meca, as a pre- and post-processing tool, is able to take solid bodies or flow volume and mesh them for use in numerical analyses, such as computational fluid dynamics (CFD).
There are a number of programs that are able to handle fluid dynamics. These range from more pure mathimatical systems that can solve the equations set up to programs created specifically to be intuitive interfaces allowing a person to set up problems as specifically as possible with a minimal need to understand how to enter new equations or the math that goes on in the background.
One program able to handle CFD is OpenFOAM. This program has a number of standard viscosity models built in, and you can add your own viscosity models as needed. It is not uncommon to see food extrudates described as power law fluids, OpenFOAM has a power law model in the current version. This program is set up to be run through a directory and file structure system. Previous version had a graphical interface that generated the files and ran the solver, but the manuals suggest the interface was removed due to issues it may have caused. While pasting, editing, and creating the files can be a little daunting at first, the procedure is actually fairly simple when you have a checklist of what to do. There does not seem to be a tutorial/checklist elsewhere for how to run an extrudate in a die, so the following link will serve as a starting point. Link to the tutorial/checklist for extrusion die CFD in OpenFOAM on foodextrusion.org.
(A Linux distribution based on Ubuntu linux – previous version was based on PCLinuxOS)
CAELinux is a linux distribution that was created
specifically for running some available engineering tools. This
distribution can be run as a LiveDVD. As a LiveDVD, you can
boot your computer to into the DVD and run the system without the
need to install it to your computer. Files can be saved on a
USB drive or other storage media. Alternately, the distribution
can be installed on the harddrive of your computer.
Tools available in CAELinux that may be useful include:
Octave (a mathematics program)
Cose Saturne (simple fluid dynamics program)
OpenFOAM (a full computational fluid dynamics program, among other analysis)
R (statistical program)
Salome Meca (pre- and post-processing tool for numerical analysis)
ParaView (a viewing tool for meshes and output from programs like OpenFOAM)
There are videos showing how to run some of the basics in the programs from start to finish for some simple systems. It does not go into great detail on more complex problems, but is enough to give a person enough information to get started with Salome Meca and OpenFOAM (and probably some other programs on the disk).