Given the adoption and success of modern GUIs across a broad range of software, you'd think that making the case for one would be redundant. However, for some reason Computational Fluid Dynamics (CFD) was a late adopter of GUIs, and for what is predominantly a visual set of disciplines - think geometry, mesh, solver feedback, 3D visualization, and 2D plots. This late adoption is still evident in CFD software today.

Modern CFD GUI: Caedium Professional

The pre-GUI era of CFD relied on state files to control various aspects of the CFD process and in some instances can still be found in use today. Many GUIs of the modern era (post-GUI revolution) are merely glorified text editors that map directly to the entries in such CFD state files. There is little, if any, continuity of GUI design between the various aspects of the CFD process. From the same software vendor you are likely to see markedly different GUIs to perform the various tasks in the CFD process, i.e., geometry creation, mesh creation, solver setup and control, 3D visualization, and 2D plots. This stovepipe set of GUIs is often reflective of the separate teams or companies that originally developed each component. Without a friction-free integration of these components you are forced to learn multiple GUI interaction models and, more often than not, have to inefficiently pass data between them explicitly.

Clearly a unified integration of all the components that make up the CFD process is going to be more efficient, but it is not sufficient to maximize an engineer's effectiveness. Standard GUI operations that have been around more or less from the beginning of the GUI era are still missing from many CFD software systems:

• Multilevel undo/redo is a simple concept that allows engineers to explore a CFD GUI environment without the penalty of making an irreversible, time-consuming mistake.
• Using intrusive dialog boxes with multiple levels of confirmation is a throwback to an era before undo/redo was widely available. Modern GUIs typically let you make changes directly to your CFD simulation without requiring confirmation and if you make a mistake you simply click undo.
• Rich visual feedback is especially useful to gauge the progress of a CFD simulation in terms of all the available 3D and 2D results (not just residual plots) updating during a simulation on a regular basis and not just at the conclusion of a simulation.
• Drag-and-drop is an intuitive operation that can be extended to many aspects of CFD in order to make the interaction more efficient.
• Multilingual localization of the GUI is essential to address the global distribution of CFD software to non-English speaking regions of the world.

"Those who don't learn from history are doomed to repeat it."

It is no fluke that Caedium addresses the shortcomings of many CFD packages - it is a conscious and difficult effort, but worth it.