Opennovation News
Engineering Consulting with Open Source Tools
November, 2008


Opennovation is an engineering consulting firm founded by Adam Powell with a focus on using and helping others to use open source software for design and analysis in engineering disciplines such as mechanics, fluid flow, heat transfer, and chemical reactor design.  Opennovation News is a means of bringing you updates on the company and the broader world of open source software for engineering.

Opennovation News is planning approximately one issue per month.  If you would like to receive it via email, please click here or send email to news@opennovation with "subscribe" in the subject.  Contributions and comments are welcome, please send them to news@opennovation.com.

Contents:

NMAB ICME event 12/10

On December 10, the National Materials Advisory Board (NMAB) will hold a "dissemination event" for the report on Integrated Computational Materials Engineering (ICME) whose final version they released in September.  The event will take place from 8:00 AM to 2:00 PM at the National Academy of Sciences Building at 2100 C Street NW, Washington, DC.

According to promotional materials, the purpose of the event is:

"...to facilitate a discussion of the barriers to implementing the vision of Integrated Computational Materials Engineering (ICME) contained in a recent NRC report.  Bringing together key stakeholders from government, industry, academia, and professional societies the forum's agenda will focus on a series of break out sessions and panel discussions focused on identifying key next steps for stakeholders to implement the report's vision of ICME."

You can read more about ICME at the National Academies ICME website, and can register online for the event (space is limited).  You can also download the report or order a hard copy.

As mentioned here before, Opennovation Principal Adam Powell is a co-author of the National Academies report, and also wrote the Wikipedia article on ICME.

Product focus: Gpiv C.S. (Contributed by Gerber van der Graaf)

Gpiv C.S. is a free/open source program for Particle Image Velocimetry (PIV), which analyzes the positions of particles in a video in order to calculate their velocity distribution over time and space.  It can quantitatively measure the flow of fluids or deformation of solids, or for any other purpose involving the deformation of an image texture over time.  For example, Gpiv turns video of tracer particles in water, tiny bubbles in transparent molten plastics, even texture on a solid surface, into a set of maps of displacements and velocities over time.

Gpiv screenshot

The Gpiv package includes a graphical user interface (GUI) through which the user can set all of the parameters (for image processing, image interrogation, PIV-data validation and PIV post-processing), run any of its calculations, and display the resulting data.  For non-interactive or background processing, the Gpivtools package provides more than forty command-line programs, scripts, and additional tools.  The Libgpiv library provides the majority of the Gpiv and Gpivtools functions, and has a Python wrapper called PyGpiv, so users can write their own programs or Python scripts to extend the functionality of the software as needed.

Gpiv uses state-of-the-art image interrogation and data validation algorithms.  The project participated in the world-wide PIV challenge project [1].  And newer methods implemented since the challenge result in even better accuracies of the PIV estimators.  A few of those include: image deformation, adaptive grid and interrogation area dimensions, PIV-data validation during the iterative interrogation using normalized residus from SNR values or from the median test, and Symetric Phase Only Filtering.

Finally, Gpiv developers have recently modified the code to run in parallel on multi-CPU computer systems and clusters, using OpenMP and MPI.  This dramatically improves the speed of image interrogation, particularly for large PIV image sets.  You can read a complete list of Gpiv features at http://gpiv.sourceforge.net/features.html.

[1] Stanislas et al., "Main results of the third international PIV challenge," Exp. Fluids 45(1):27-71 (July 2008), DOI 10.1007/s00348-008-0462-z.

Product focus: Elmer

Elmer is an open source (GPL) suite for performing engineering simulations using the finite element method (FEM, or finite element analysis, FEA).  Its authors and primary contributors are at CSC Scientific Computing Ltd. in Finland.

Carotid artery during blood flow surge

Elmer's 33 "Models", or equations, can solve a wide variety of problems, from heat conduction (temperature distribution in a solid) to turbulent fluid-structure interactions (e.g. carotid artery deformation due to pressure surge during a heartbeat, right; click for animation) to electromagnetics.  Its 2-D Level Set solver can solve multi-phase flow problems such as bubble deformation.  It can even use the finite element method for Density Functional Theory quantum mechanics calculations, in order to calculate molecule shapes or crystal structures and energies.  And beyond finite elements, it can do boundary element calculations, and has code for calculating heat transfer by thermal radiation between surfaces, and for simulating low-pressure gas flow using the Direct Simulation Monte Carlo method.  All of these models can connect to finite element simulations.

Elmer does not have its own geometry definition or meshing program.  Instead, its ElmerGrid program can import meshes in fifteen different formats, such as those of Gmsh, Salomé, ANSYS, ABAQUS, FIDAP and COMSOL.

Perhaps most importantly, all of this capability comes with very extensive and easy-to-read documentation, including several tutorials with input files which describe how to use its extensive graphical user interface (GUI) called ElmerFront to solve simple and complex problems.

A new GUI called ElmerGUI currently under development will make all of this even easier.  This GUI can directly import meshes in the fifteen formats of ElmerGrid, and links with OpenCASCADE and NETGEN to directly import and mesh CAD files in IGES, STEP, BREP and STL formats.  One can point-and-click to set boundary conditions and equations.  And it has a new module for visualizing the resulting temperatures, flow velocities, etc. based on VTK.

Elmer also runs in parallel, using either the (P)ARPACK solver or the UMFPACK direct solver which is more robust but slower.

For those who prefer writing their own finite element program, Elmer has its own library called libelmersolver, which is similar to libMesh and deal.II.

Elmer is in the Opennovation Debian (Lenny) and Ubuntu (Hardy) repositories, so you can automatically download and install it along with all of its dependencies using Synaptic, Aptitude, or simply "apt-get install elmer".

Happy holidays from Opennovation!

The Opennovation press, media, software development, packaging, and consulting staff would like to wish you and your loved ones a wonderful holiday season.

This first year of Opennovation News has been an exciting one for open source engineering software, as several new products and new releases have made it possible to do more with design and analysis at lower cost and with greater flexibility than ever before.  The Opennovation Debian and Ubuntu software repositories mentioned above have also made it very easy to download, install, and rapidly start using these tools.  This is particularly important for businesses interested in doing new product development at low cost during the economic downturn, in order to emerge more competitive when the economy recovers.

In the new year, in addition to more developments in this same vein, Opennovation is planning to release original work in software for electrochemistry simulation, and to collaborate with colleagues at Purdue, Texas A&M and NIST on an open source ICME stack, from quantum mechanics to statistical mechanics, CALPHAD thermodynamics, and phase field structure calculations.

Special thanks to those who helped to make last months North Shore Technology Council breakfast entitled "Powering Up Massachusetts' Sustainable Energy Industry" such a success. The total attendance of 101 people set a new NSTC record!

Opennovation News will take a hiatus in December as the whole staff travels to Thailand to participate in Third International Conference on Processing Materials for Properties PMP-III. Best wishes for safe travels and blessings to you and your loved ones through the remainder of 2008.