COMSOL 6.4 - Continuity

The node, exists as an option at interfaces between parts in an assembly, from the submenu. The condition is similar to the Material Discontinuity condition that applies to interior boundaries. The difference is that the condition should also be applied when the same material exists on both sides of a pair. The advantage of using a pair feature is that the mesh does not need to be conforming on the two sides of the interface (the two parts pf the assembly). This is especially advantageous for the time explicit discontinuous Galerkin method as the time step depends on mesh size and local speed of sound.

The condition implements continuity in total pressure and in the normal velocity over the pair:

Subscripts “src” and “dst” in the equation refer to the source and destination in the pair; that is, the two sides in the pair.

	For more details on using assemblies and the pair features see Assemblies and Pair Conditions in the Modeling with the Pressure Acoustics Branch (DG-FEM-Based Interface) section.

	This feature is not available when Use accelerated solver formulation is enabled.

The time-explicit DG-FEM method uses an efficient quadrature free computation of the boundary flux. This can in certain cases result in unstable behavior when pair conditions are used with non-conforming meshes. To remedy this a more accurate projection based quadrature method is used (per default) on all pair conditions, such as the condition.

Click to select (selected per default).