Introduction to OpenFoam® and chtMultiRegion using an application-oriented example

In the course of the work on the AM 4 Industry project, research on the design and simulation of near-contour cooling channels was carried out. One objective was to provide toolmaking engineers with an instrument that could be used to further optimise cooling channel geometries. Particularly in the design of near-contour and irregular cooling channels, simulation using commercial simulation programs may not be sufficient and thus require additional simulation steps. For this additional or supplementary simulation step, the focus was deliberately placed on a non-commercial simulation program. Therefore, the program OpenFoam® (Open Source Field Operation and Manipulation) was chosen for the simulations. This is freely available and is mainly used to solve flow problems (Computational Fluid Dynamics). It is written in C++ and comes with useful solvers even in the basic version, and a wide variety of further solvers can be adapted. One of the major advantages is that the source code and thus also the algorithms are freely accessible; and another, that the codes and calculations can be extended almost arbitrarily.
Based on an application-oriented example, this manual describes the structure and the
performance of a simulation in detail. The solver chtMultiRegion was used for the simulations. This is generally used to calculate the heat exchange between a solid and a fluid.
The objective of this manual is to give users in development, simulation engineers and students an application-oriented introduction to OpenFoam®, as well as an overview of how to work with it. The individual steps were grouped into nine chapters with the following contents:

• Chapters 1 and 2 give a general overview of the simulation example as well as of the simulation structures of OpenFoam®
• Chapters 3 to 6 show how a simulation case is set up in OpenFoam®, and which settings are required. The creation of the calculation mesh and the allocation of the surfaces are dealt with in detail.
• Chapters 7 and 8 address the performance of the simulation. The choice of the boundary condition and the theory of flow simulation are dealt with.
• Chapter 9 concludes by discussing the evaluation methods offered by OpenFoam®, and how the results can be exported for further processing.

Finally, it should be mentioned that the OpenFoam® environment may seem strange at first glance, especially for users accustomed to Windows® operating systems. Patience is definitely required here. It simply takes time for the program’s processes to be perceived as logical, and to become proficient in the commands necessary for the operation and execution of the program. However, it will certainly be worthwhile to get deeply into this topic, as it offers the possibility to further refine one’s simulations and make better predictions. This may in turn provide a clear competitive advantage. Thus: Happy Foaming!