With artificial viscosity and total variation diminishing advection limiter, the edge-centered artificial viscosity with structure zones is extended to unstructured grids, The limiter is constructed by neighbor edges determined by maximum angle choice. The edge-centered artificial viscosity is compared with the zone-centered artificial viscosity. Numerical results demonstrate accuracy and efficiency of the edgecentered artificial viscosity in capturing shock discontinuous.

The subzonal pressure is obtained with subzonal Lagranian masses and corresponding densities. It results in subzonal corner forces and eliminates hourglass motion and spurious vorticity.We extend the compatible Lagranian hydrodynamics algorithm including subzonal pressures to unstructured zone and develope the code.Numerical examples of Saltzman piston demonstraste that this algorithm captures shock discontinuity,eliminates hourglass motion and restraines spurious vorticity accuratly and efficiently.

Based on Noh's artificial viscosity with artificial heat flux method(Q & H),we present a Q & H scheme on arbitrary n-polygon meshes.Noh's Q & H on structured meshes is extended to unstructured meshes in two dimensions.Numerical results of Noh's problem and collision of two metals show that the Q&H method on unstructured meshes eliminates wall heating effectivly.

A scheme for unstructured quadrilateral mesh generation based on Delaunay triangulation is presented.With a front edge definition we mark a triangle mesh in the front edge.According to triangle mesh shape and directionality two triangular meshes are merged into a quadrilateral mesh. A 100% quadrilateral mesh obtained converts a quad-dominant to an allquad mesh with mesh conversion templates.Numerical results are shown.