Below are quick answers to common questions about licensing, meshing, solver runs, and results viewing in CFxD.
Does CFxD start in Demo mode?
Yes. CFxD runs in Demo mode by default. Demo limitations typically include a mesh-size limit and single-core usage.
How do I remove Demo limitations?
Purchase and activate a license from within the application (License / Buy section).
Do I need an internet connection?
An internet connection is required for checking updates and verifying license status. Most day-to-day work can be done offline once the software is installed and run.
Can I move a license to another PC?
The license is tied to the hardware. Please contact support to transfer a license to a different computer.
Installation & Updates
The installer is blocked by Windows SmartScreen. What should I do?
Click More info → Run anyway (only if you downloaded CFxD from the official CFxD website).
Where is CFxD installed?
By default, CFxD installs into a standard Program Files location (recommended). You can choose a custom folder during installation.
How do updates work?
CFxD can check for updates and install newer builds automatically from within the application.
Meshing
My mesh fails to generate. What are the usual causes?
Common causes include:
- Missing Microsoft MPI installation (required for multi-core simulation).
- Very small features relative to the base mesh size.
- Invalid or missing boundary naming / patch definitions.
Try simplifying the geometry, increasing the base cell size, or fixing boundary definitions.
How do I improve mesh quality?
Start with a coarser mesh and refine gradually. Review mesh diagnostics (orthogonality/skewness if available), then adjust refinement and layer settings. Avoid extreme refinement near tiny features unless necessary.
Why is the cell count much higher than expected?
High refinement levels and wall treatment (prism layers) can increase the cell count quickly. Reduce refinement levels, disable wall treatment, or increase the base cell size.
Solver / Runs
Which solver should I choose?
Currently, CFxD supports:
- Steady-state
- Incompressible/compressible(M<1) flows
- Heat transfer (natural/forced convection)
My run is slow. What can I do?
- Use a coarser mesh for early iterations.
- Ensure you are using multi-core execution (requires a BASIC license and Microsoft MPI installed).
Residuals do not converge. Is it always a problem?
Not always. Some flows converge to a statistically steady state or show oscillations. Use engineering checks (mass/energy balance and monitored quantities) in addition to residuals.
Results / Post-processing
I don’t see results after the run.
Check:
- The case finished successfully and wrote time folders.
- Fields exist for the variables you’re trying to view (e.g., p, U, T).
If nothing is written, verify solver control and write settings.
Contours or vectors show nothing / are blank.
Common causes include:
- The Result folder was accidentally deleted, moved, or overwritten.
- The Solution stage was incorrectly finished.
How do I export images or reports?
Images are saved in the Result folder. CFxD can automatically generate a PDF report containing images and key input data.
Project & Files
Where are my projects stored?
By default, projects are saved on the C: drive. Project names are generated automatically (e.g., Project(1), Project(2)).
Can I share a project with someone else?
Yes—share the entire project folder (including case files and result folders). The other computer requires CFxD installation and a valid license.
Still stuck?
If your question isn’t covered here, post on the Forum with:
- CFxD version
- OS (Windows 10/11)
- Workflow step (Geometry / Mesh / Setup / Solve / Results)
- Error log text and screenshots