Revision as of 10:53, 27 May 2014

Introduction

Elmer is an open source (GPL) computational tool for multi-physics problems. It is developed by CSC in collaboration with Finnish universities, research laboratories and industry. To test ONELAB models working with Elmer, you first need to install the generic ONELAB virtual machine on your system by following these instructions. When done, you can log in into the virtual machine (username: "olvm", passwd: olvm) and proceed with the installation of the Elmer software, and the download of benchmark ONELAB models. The instructions to do so are given in the next section.

Installation

The Virtual machine is configured so that Gmsh and Elmer can be installed straightforwardly by issuing simple commands in a terminal. Proceed as follows.

Step 1

Download installation scripts

Open a terminal by clicking on the "terminal" icon in the launcher panel and issue the command

install_scripts.sh

Then, the command

install_gmsh.sh

will download the nightly-build of Gmsh from http://geuz.org/gmsh, install it, and place a Gmsh icon on the Desktop.

When done, issue the command

install_elmer.sh

which will download the source code of Elmer and compile it on the virtual machine. This may take several minutes.

Now, you have a woking installation of Gmsh and Elmer on the virtual machine. A number of Elmer model examples can be downloaded by issuing the command

getElmerModels.sh

After all, you have a directory "ELMERMODELS" in your home directory with a number of Elmer models, which are now presented with more details.

ONELAB models

Cryotherapy

Beam3D

Laser

Drug patch

LASER

Download and inflate the archive LASER.zip in a work directory. Right-click on the icon laser.ol and open the file with gmsh. Alternatively, start gmsh and click File > Open > laser.ol from the menu.

The physical background of this model is the laser stimulation of skin in order to measure the density of nociceptive receptors. For a correct interpretation of the experimental data, an accurate knowledge of the temperature distribution in time and across the skin is needed. The metamodel allows selecting various laser types (Gaussian, flat-top) and various stimulus characteristics (imposed flux or controlled temperature). Each simulation generates a graphical result file plot.pdf that is directly interpretable by clinicians.