Click (Mesh tab > Mesh Diagnostics panel > Mesh Statistics). The mesh match percentage, and reciprocal match Percentage should be at least 80-85%.
Click (Mesh tab > Mesh Diagnostics panel > Mesh Match) and click Show. The Dual Domain mesh match information is displayed on the model as a plot, and highlights all elements that are Matched, Unmatched, or on an Edge.
A useful technique for visualizing the element matching is to shrink the elements:
On the Layers pane, click the layer containing the Dual Domain mesh elements to select it.
Click Display to access the display properties of the layer.
In the Entity type drop-down menu, select Triangle element.
In the Show as drop-down menu, select Shrunken.
Press Ctrl-D to turn the diagnostic plot off.
Press Ctrl-D to turn the diagnostic plot on again.