The Normal Velocity adds an inward normal velocity vn(t) or specify the acceleration v0(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 time derivative of the velocity an(t) = vn(t)/t. 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 Velocity (the default) or Velocity.