No-slip surfaces show non-zero velocities in ParaView

[wyldckat]

For example, the tutorial 'incompressible/simpleFoam/motorBike' shows non-zero velocities on the surfaces of the pilot and motorbike, when it should instead show zero.

Specifically, this is visible when only the patches for the pilot and motorbike are selected in the Mesh Regions entry, without the
internalMesh being selected.

[wyldckat]

Reason

The boundary condition noSlip is not properly interpreted by VTK/ParaView, which results in VTK/ParaView assuming that this is a zero-gradient boudary condition.

This boundary condition was introduced to OpenFOAM in commit ab3081aa6bb and it is not yet supported in VTK/ParaView.

See the first bug report in OpenFOAM Foundation's bug tracker on this topic, namely issue #2298.

Note: This should be fixed when the following report is solved: Issue #16873 in VTK's project

Solution

The simplest workaround is to run:

foamToVTK

and open the VTK\*.vtk files in ParaView, in order to have the correct data representation.