Please be aware this website makes use of Google Analytics tracking software which will use cookies downloaded to your computer.

Welcome to the HR Wallingford FluidEarth training website. This website gives you all of the tools and examples you’ll need to get up and running with OpenMI and FluidEarth version 2.2 for Windows with .NET, together with detailed instructions and videos guiding you through each step in the process. All of the tools and training examples supplied here are free for you to use and are also Open Source to enable you to adapt and modify them. You should be able to get your first OpenMI version 2.0 composition up and running within 1 hour!

Please note that some minor differences in the user interface between 2.0 and 2.2 will mean that some video tutorials are slightly out of date but this will have no material effect on the tutorial.

We have adopted the use of Microsoft Visual Studio 2010 throughout and a target environment of .NET 4.0. In addition, the projects we develop in this tutorial will be targeted at the x86 platform.

For background information about OpenMI, please visit the OpenMI Association Website at: For background information about FluidEarth, please visit the FluidEarth portal at:

The OpenMI standard has now reached version 2.0 with many improvements over the previous version, 1.4. FluidEarth has supplied the non-Java reference implementations of two tools which are pledged by the OpenMI Association to accompany every release of the standard:

  1. A Software Development Kit (SDK), the FluidEarth SDK, allowing model developers to easily make their model engines OpenMI compliant and,
  2. A Graphical User Interface (GUI), Pipistrelle, allowing model users to build and run compositions of OpenMI compliant components. Both of these tools existed for OpenMI 1.4 and the OpenMI 2.0 versions are upgrades of these. You can still download the 1.4 versions from the FluidEarth portal and view the 1.4 training provided there, however, these versions have a lower degree of support than those for OpenMI 2.0. It is recommended that you use the OpenMI 2.0 tools.

The training materials on this site will show you :

  • how to download and install the Pipistrelle GUI, FluidEarth SDK and FluidEarth Tutorial packages;
  • how to build Open MI 2.0 compliant components and adapters in C# and Fortran;
  • how to run an Open MI 2.0 composition using Pipistrelle 2.2;
  • how to convert your existing Open MI 1.4 components to be Open MI 2.0 compliant.

In order to introduce the fundamental concepts of OpenMI 2.0 and its implementation with FluidEarth, the first compositions you build will consist of very basic components. As you progress through the steps, the components become more complicated and explore some of the new concepts in OpenMI version 2.0. In particular, adapted outputs are demonstrated. These provide a method of passing data between two model components where the output of one component requires some adaptation (due to different geometries, for example) before being input into the next.

All of the training components are provided with source code. The tutorials are all developed to a standard version of the SDK and Pipistrelle. These tools are Open Source and so may have since been modified by the community; the versions used here together with the very latest developments are stored in the FluidEarth Source Forge project.

Now follow the instructions for configuring your development environment, then go on to design a simple component and read the section on the OMI file. You should then be ready to select the tutorial for your chosen development language.