The use of non-uniform rational B-Splines in overset grid generation

The overlapping grid technique has been in use for more than a decade and a half now. Although there have been many advances during that time, there are still many problems both for the generation of good overlapping grids and their use for accurate solutions of Partial Differential Equations (PDEs). The objective of this study is to extend the capability in overlapping grid method by an analytical approach. A Non-Uniform Rational B-Spline (NURBS) technique is introduced in overset grid generation. The hole-cutting process, which is crucial in overset grid generation, is accomplished using the NURBS formulation. An automatic hole-cutting algorithm is combined with a grid redistribution method to ensure overset grids with high quality. A binary search algorithm to speed up the hole-cutting process is also presented. The binary search algorithm reduces the number of search iterations by an order of binary logarithm.; The automation feature in this NURBS-based Chimera method reduces the response time and results in an efficient overset grid system that can be used for flow simulations. Computational grids generated for both internal and external flow applications are presented to illustrate the utility of this technique.