. Select Mesh->Element type->Quadrilateral . Select surfaces number 24 and 12 and press ESC.
. Select Mesh->Generate mesh.
. A window comes up asking whether the previous mesh should be eliminated. Click Yes.
. Another window appears in which the maximum element size can be entered. Leave the default value unaltered and click OK. The result will be the mesh illustrated in Figure 6.
. The surface is meshed with quadrilaterals, forming an unstructured mesh, surface 12 seems structured but if you zoom in, you will see that it is not.
