Direct method to supply background information for the generation of unstructured grid

Based on the distribution law of potential functions induced by point and line sources and the characters of outer circumfluence, the direct method to supply information parameters of background grid was developed to control grid distribution in the generation of unstructured grid, and the unstructured grids were generated by the advanced front method. The directional control switching was applied to the induced potential function of partial point and line sources to make the distribution of the generated grid be in keeping with the expected law. The results of the grid generation of flow field for several airfoils have shown that the method has advantage over the conventional background grid generator in amount of computation, continuity, smoothness and flexibility.