Free surface (potential)
Potential free-surface flow in OpenFOAM: a water line without tracking the interface
Model a free surface as a moving boundary rather than as a tracked interface — much cheaper than VoF where the surface stays smooth and unbroken.
What it is
The water surface is treated as a deforming boundary on a single-phase domain, so there is no volume fraction to advect and no interface smearing to fight. It holds while the surface stays continuous, and stops holding the moment it breaks, overturns or entrains air.
What the application sets up
- A single-phase domain with the free surface as a boundary
- Inlet and outlet conditions consistent with the expected water line
- Mesh grading towards the surface where the deformation happens
- Surface elevation output, which is the field being sought
- A check on whether the surface stays unbroken, since that is the model's limit
Typical uses
- Steady hull resistance and wave patterns
- Channel and weir flow with a smooth surface
- Early-stage hull form comparison, before a full VoF run
- Cases where VoF would spend its budget resolving an interface that never breaks
Industries
Sectors where this analysis is routinely asked for.
- Naval architecture
- Marine consultancy
- Canal & waterway engineering
- Early-stage hull design
What comes out
- Wave pattern and elevation
- Hull resistance trend
- Trim and sinkage indication
- Candidate hull ranking
OpenFOAM solvers
potentialFreeSurfaceFoam
Selected and configured for you from the analysis type. You can still see every dictionary the application writes.
In every tier
This analysis type is in the free build. The free tier limits mesh size to 250,000 cells and solving to one core — not which physics you may use.
On accuracy, plainly.