Unstructured Triangulation Grid Generation And It's Application In 2D Hydrodynamics Model

Unstructured grid generation techniques have been made great progress in recentyears, especially with the development of computer science. Without the restrictionsof the structure of gird nodes, the nodes and elements of unstructured grids can bedistribute arbitrarily, so they are applicable to very complex geometrical domains.Once the distribution of boundary nodes is given, unstructured grids usually can begenerated automatically. In this paper, the unstructured gird is generated with numerical method based onthe conception of Delaunay Triangulation. Meanwhile, improvements have been madeto the date structure used in Delaunay triangulation pioneered by A.Bowyer, whichenable the method to insert, delete, search date more conveniently and quickly.Mesh-generating speed is also improved. It has the power of generating good qualitygrids for complicated shapes whose detail sizes are much smaller than that of theoverall shape and forming denser grids in detail places, based on domain grid gradingpropagation. Some methods are given to delete the unprotruding domain ,smooththe grid and resume the losing boundary. This method can adapt a random complexgeometry boundary. And the density of the generated grid can be adjusted accordingto the restriction of the size. An automatic 2D mesh-generating program is madeunder windows system using Visual C++.The two dimensional hydrodynamics model is solved numerically with FiniteVolume Method based on unstructured triangulation grid. Numerical experimentsshow that the numerical model is effective to compute the tidal current in the coastalarea with complex boundaries.