Table 2: Selection of numerical elements used in studies.

Element Type Freq. of Usage for Group 1 Papers 2005-2010 Freq. of Usage for Group 2 Papers 2010-2013 Dimension
Hexahedral 3 6 3D
Tetrahedral 2 5 3D
Prismatic 1 3 3D
Irregular 2 0 3D
Triangular 3 1 2D
Quadrilateral 1 0 2D
Rectangular 1 2 2D
Unspecified or non-applicable 27 39