ON THE FOLDING OF NUMERICALLY GENERATED GRIDS: USE OF A REFERENCE GRID.

When variational grid generation techniques are used to produce grids suitable for solving numerical partial differential equations in irregular geometrics, a reference grid can be used to determine the properties of the desired grid. Grid folding is a major problem in all methods of numerical grid generation; this paper studies the use of a reference grid, in variational smoothing methods, to prevent such foldings. The effects of various types of reference grid are compared and natural reference grids are shown to prevent foldings in the examples studied. The analysis is performed for a model problem with only one free point, and is then applied for finer grids. In addition, a short description of a discrete variational method is given. The reference grid concept applies to this discrete formulation. [ABSTRACT FROM AUTHOR]