Abstract: The response of background grid to source element is of great significance in generation of unstructured grids,and if the response can just right display the source element in background grid, the grids generated will meet more the requirements of its initial design.A new method of background grid respond to source element for generation of unstructured grids is presented. Being different from the other method, the triangular element is used as the background grid, and according to the location of a source element, the triangular element is divided into seven sub-fields. To each source element both the element considered and the sub-field in which it is located are distinguished and then the element node is adjusted or the background grid topological structure is changed,so that every source element will be just located at a corresponding node of background grid. The spacing parameters of grid points are distributed over the nodes of background grid by solving a Poisson equation using the control volume finite element method and will be much better to meet the requirement of the designed, so that this way can provide better grid quality by using the advancing-front method. Some samples of two-dimensional grids are presented and demonstrate the merits of this method.

Key words: background grid, source element, automatic response, advancing front method, unstructured grid