Introduction

FreeFEM is an open source finite element software used to solve partial differential equations. It can be used to simulate all kind of physics and even multi physics problems. A user should have a good understanding of the different integral formulations, as the FreeFEM code is very close to mathematics. Running your FreeFEM simulation on Qarnot is as easy as uploading your case and launching a script. Here’s a walk-through of the different steps.

Versions

The test case uses FreeFEM 4.4-1.

If you are interested in another version, please send us an email at qlab@qarnot.com.

Test case

Please ensure that you have created a Qarnot account here.

This test case is based on the Projection Algorithm for the Navier-Stokes Equations example. You can download the case folder here, which contains the case script. You should put it at the same folder level as the script to launch the calculation. Please note that it needs to be unzipped before it can be used on Qarnot.

Launching the case

Before starting a calculation with the Python SDK, a few steps are required:

• Retrieve the authentication token (here)
• Install Qarnot’s Python SDK (here)

Note: in addition to the Python SDK, Qarnot provides C# and Node.js SDKs and a Command Line.
Once everything is set up, the following script needs to be used to start the calculation.

Be sure you have copied your authentication token in the script (instead of <<<MY_SECRET_TOKEN>>>) to be able to launch the task on Qarnot.

freefem.py

To launch this script, simply copy the preceding code in a Python script, put at the same level as the navierstokes folder and execute python3 freefem.py & in your terminal. You should copy the gist code (as shown here) and not the raw code.

Results

At any given time, you can monitor the status of your task on the general web interface Console. When the simulation is completed, all its numerical results are available in the output bucket. You can force preview as an image both .eps files to show the results. The following figure shows the output bucket of a successful FreeFEM demo simulation on Qarnot’s console.

You should also now have a result folder on your computer containing all the numerical results. 

Wrapping up

That’s it! If you have any questions, please contact qlab@qarnot.com and we will help you with pleasure!
You can read more about a use case of OpenFoam on Qarnot here : Finite Elements on Qarnot.