The Normal Displacement adds an inward normal displacement dn(t) or specify the acceleration d0(t) of the boundary. The part in the normal direction is used to define the boundary condition. The condition is very similar to the Normal Acceleration condition having the acceleration given by the double time derivative of the displacement an(t) = 2dn(t)/t2. This feature represents an external source term. It can also be used to manually couple acoustics with a structural analysis for modeling acoustic-structure interaction.

Select a Type: Inward Displacement (the default) or Displacement.