Symbolic Local Refinement of Tetrahedral Grids

A recent local grid refinement algorithm for simplicial grids is shown to be suitable for symbolic implementation in the 3-dimensional case. An addressing scheme stores all the geometric information about the tetrahedra in the refinement tree. Location of vertices and the addresses of physically nearest neighbors are computed by decoding the symbols of the simplex address. Bisection and face-compatible refinement of the simplex and its splitting neighbors are obtained by symbolic and logical operations on the leaves of the tree.