Particle-Wall Link Model Reference

Once a particle links to a wall boundary, its translational velocity is always the same as that of the point on the boundary it is linked to. The particle keeps a fixed orientation relative to the local surface normal. This local surface normal is a smoothed, continuous normal interpolated at the link point if the tangential velocity is non-zero. If the tangential velocity is zero, the local surface normal corresponds to the face normal. If a particle moves from a linked to an unlinked boundary, that particle is removed from the simulation.

Removing links can result in large particle velocities if overlap of particle and wall is large. Regenerating a mesh is likely to cause such link removals.

Particles do not form links to interface boundaries.

For particle clumps, individual particles within the clump can be designated as available for linking on contact. See Link to Boundary under Sphere Properties.

The Particle-Wall Link model does not operate on the same particles as other mechanical contact models such as Hertz-Mindlin or Linear Spring. When the Particle-Wall Link model is selected, the properties specified in other mechanical contact models have no effect on spheres that have made contact and become linked to the wall. In particular, there is no effect on heat transfer contact models, the forces exerted by linked particles, or the contact models for other DEM particles in the simulation.

The Particle-Wall Link model is compatible with DFBI motion. In DFBI, the linked particle does not exert contact force on the wall; forces on the particle are transmitted directly to the wall. The particle is treated as part of the wall.