Ansys Meshing – Pinch

Pinch removes the slivers a mesh produces where a geometry has very thin regions: narrow gaps, sharp wedges, small steps. Instead of forcing tiny cells to fit them, the mesher collapses the nodes on the smaller side into the larger one.

You set a tolerance, and features below it get pinched at mesh level. The geometry itself is untouched, which is what separates this from repairing the CAD model: it is a local simplification applied while the mesh is generated.

The trade-off is fidelity. Pinching a feature that actually matters, a real gap in a valve for example, silently changes the physics you are solving. Use it for artefacts of the CAD model, not for features the flow depends on.