The Added Mass node is available on domains, boundaries, and edges and can be used to supply inertia that is not part of the material itself. Such inertia does not need to be isotropic, in the sense that the inertial effects are not the same in all directions.
The Added Mass node is only available with some COMSOL products (see
http://www.comsol.com/products/specifications/).
Select a Mass type using
Table 4-10 as a guide. The default option is the type for the geometric entity. The added mass matrix can be entered as
Isotropic,
Diagonal, or
Symmetric. For
Isotropic the same mass is used in all the diagonal elements of the mass matrix.
Select the Exclude contribution check box to switch off the loads that can be caused by the added mass when the frame is accelerated when using a
Gravity or
Rotating Frame feature. The setting will also determine whether the node will contribute when
Computing Mass Properties.