Finite-volume discretizations can be formulated on unstructured meshes composed of different polygons. A staggered cell-vertex finite-volume discretization of shallow water equations is analyzed on mixed meshes composed of triangles and quads. Although triangular meshes are most flexible geometrically, quads are more efficient numerically and do not support spurious inertial modes of triangular...

IO tools in numerical simulations often serve two functions, one for writing and reading files to restart calculations and the other for writing and processing diagnostic files including files for graphics post-processing. For diagnostic files, tools directly working for high-level data structures are desired, such meshes with adaptive mesh refinement, unstructured meshes, and association betwe...

Volume Rendering of time-varying datasets is essential in several scientific applications. Due to the enormous amount of data involved, in datasets with static sampling regions it is common to consider only time-varying scalar fields (TVSFs). The use of Vector Quantization (VQ) to compress scalar fields has been shown to be quite effective when combined with texture-based volume rendering algor...

We further study the properties of the back and forth error compensation and correction (BFECC) method for advection equations such as those related to the level set method and for solving Hamilton-Jacobi equations on unstructured meshes. In particular, we develop a new limiting strategy which requires another backward advection in time so that overshoots/undershoots on the new time level get e...

accurate prediction of pollution control and environmental protection need a good understanding of pollutant dynamics. numerical model techniques are important apparatus in this research area. so a 2500 line fortran 95 version code was conducted in which using approximate riemann solver, couples the shallow water and pollution transport agents in two dimensions by the aid of unstructured meshes...

The co-volume integration method, Yee’s scheme, generalized to unstructured mesh is considered and compared with time domain finite element method (TDFE). In order to generate the meshes for which a good quality dual mesh is ensured, a new point placing method for the generation of meshes appropriate for the use of the co-volume method is proposed. Numerical examples are presented which demonst...

Several algorithms for generating two-dimensional unstructured meshes use triangle insertion and removal as their basic operations. This work presents a robust mathematical framework, based on Morse Theory, which allows full control of the topological changes caused by the insertion or removal of triangles into 2D meshes. Topological control is ensured by a set of Morse operators and simplifies...

In this paper, we present a topological neighborhood expression which allows us to express arbitrary neighborhood around cells in unstructured meshes. We show that the expression can be evaluated by traversing the connectivity information of the meshes. We implemented two algebraic operators which use the expression to compute neighbors of cells and approximate data fields of cells by aggregati...

The solution of partial differential equations on a parallel computer is usually done by a data parallel approach. The grid is partitioned and mapped onto the processors. However, partitioning of unstructured meshes and adaptively refined meshes in general is an NP -hard problem and heuristics are needed. In this paper a parallelisable and cheap method based on space-filling curves is analysed....