MESHING ALGORITHMS

Presented by

Gopi Krishna (13MCD1053)

Vikas (13MCD1054)

What is a mesh

• MESH represents a discretization of a geometrical CAD model into a set of entities with a simple topology.

The topology of a mesh is described by the relationships between its entities including:

• Node — 0D object of a mesh presented by a point with coordinates (x, y, z).

• Edge — 1D element of a mesh defined by two nodes.• Face — 2D element of a mesh defined by three or four

edges (closed contour).• Volume — 3D element of a mesh defined by several faces.

     These entities are considered as topological entities and they don't imply any geometric representation. Only Nodes reference geometric representations of points with definite coordinates. The node entity will contain additional information about its position in the space and its relations with the meshed CAD model.

Types of mesh

Two dimensional:-• Triangle

This cell shape consists of 3 sides and is one of the simplest types of mesh. A triangular surface mesh is always quick and easy to create. It is most common in unstructured grids.

• Quadrilateral

This cell shape is a basic 4 sided one. It is most common in structured grids.

Three dimensional • Pyramid

These are effectively used as transition elements between one type of elements and other in hybrid meshes and grids.

• Prism with triangular base

The advantage with this type of layer is that it resolves boundary layer efficiently.

• Tetrahedron

In most cases a tetrahedral volume mesh is generated automatically.

• Hexahedron

For the same cell amount, the accuracy of solutions in hexahedral meshes is the highest.

diagrams

GRID

• A grid is an arrangement of shapes. Grids play a crucial but invisible role in geometrical design. They provide the underlying structure for a composition. They allow a designer to make the first creative steps when contemplating a new composition. 

• Grids allow a designer to easily alter the size of a composition without having to redesign or recalculate. Grids allow a designer to use one grid design but still create a variety of different geometrical compositions.

TYPES OF GRID

Defining 3d Meshing Algorithm

Construction of Mesh using Ghs3D algorithm

• Ghs3d is a fully automatic tetrahedral mesh generator suitable to create volume meshes for complex domains defined by a conforming mesh of the boundary (i.e., a surface triangulation).

• The volume mesh is governed by the properties of the surface mesh given as input.

Gopi Krishna Vikas