ADAPTIVE-HARMONIC STRUCTURED GRID GENERATOR


At the Computing Center of the Russian Academy of Sciences the group of researchers headed by Dr S.A.Ivanenko developes the ADAPTIVE-HARMONIC STRUCTURED GRID GENERATOR Grid generating algorithm, which guarantees the convexity of all grid cells in 2D was proposed in paper [1]. It was applied to a series of two-dimensional domains of very complex shape. Satisfactory grids were obtained in all cases. This method is a variational generalization of the Winslow method and solves the problem of unconditional minimization of the functional, which depends only on the coordinates of the grid nodes. The use of grid convexity concept in the algorithm ensures a one-to-one discrete mapping. On the other hand, this method removes the necessity of splitting domain into blocks, and allows to build structured grids over the entire domain. On the basis of this algorithm we developed interactive 2D Grid Generator providing an easy way to construct different grids even for very complex domains without human expense and ingenuity. The program runs under MS Windows 3.0. A new method of grid adaption has been developed [2]. The method is based on a variational formulation for the problem of constructing the harmonic coordinates on the surface - the graph of control function. The process of grid adaptation starts with the construction of a uniform grid on hypersurface of control function values, and then projecting this grid back to the computational domain. This method is a generalization of method [1]. It can be proved that all cells of generated grids are convex quadrilaterals. The generalization to the case of structured/unstructured 3D and surface grids is under construction.

Literature

1. Ivanenko S.A. and Charakhch'yan A.A. Curvilinear grids of convex quadrilaterals. USSR Comput.Maths.Math.Phys, vol.28, N2, pp. 126-133, 1988. 2. Ivanenko S.A. Adaptive grids and grids on surfaces. Comput. Maths. Math. Phys. vol.33, N8, pp. 1333-1350, 1993.

Contact address:

Dr. Sergey Ivanenko Computing Center of the Russian Academy of Sciences, Vavilov Str. 40, Moscow 117967, Russia. Telephone: (095) 135-2109 Fax: 007 095 135-6159 E-mail: sivan@ccas.ru or sivan@sms.ccas.msk.su