Prismatic versus tetrahedral elements in three-dimensional finite element analyses of subsurface systems

A mesh of prismatic or tetrahedral elements automatically generated from an initial triangular grid is used to integrate 3-D flow equation in space. Many numerical comparisons between these two models have been performed. The results show that integration with tetrahedrons is as accurate as integration with prisms but much more efficient. The CPU time of solution with prismatic elements is about three times greater than that required employing tetrahedral elemen