man mkgeo_grid (1): build a strutured mesh of a parallelotope, in 1d, 2d or 3d

SYNOPSIS

mkgeo_grid options [nx [ny [nz]]]

EXAMPLE

The following command build a triangular based 2d 10x10 grid of the unit square:

        mkgeo_grid -t 10 > square-10.geo
        geo square-10.geo

or in one comand line:

        mkgeo_grid -t 10 | geo -

DESCRIPTION

This command is usefull when testing programs on simple geometries. It avoid the preparation of an input file for a mesh generator. The optional nx, ny and nz arguments are integer that specifies the subdivision in each direction. By default nx=10, ny=nx and nz=ny. The mesh files goes on standard output.

The command supports all the possible element types: edges, triangles, rectangles, tetraedra, prisms and hexahedra.

ELEMENT TYPE OPTIONS

-e: 1d mesh using edges.
-t: 2d mesh using triangles.
-q: 2d mesh using quadrangles (rectangles).
-T: 3d mesh using tetraedra.
-P: 3d mesh using prisms.
-H: 3d mesh using hexahedra.

THE GEOMETRY

The geometry can be any [a,b] segment, [a,b]x[c,d] rectangle or [a,b]x[c,d]x[f,g] parallelotope. By default a=c=f=0 and b=d=g=1, thus, the unit boxes are considered. For instance, the following command meshes the [-2,2]x[-1.5, 1.5] rectangle:

        mkgeo_grid -t 10 -a -2 -b 2 -c -1.5 -d 1.5 | geo -

-a float
-b float
-c float
-d float
-f float
-g float

BOUNDARY DOMAINS

-sides

-nosides

The boundary sides are representd by domains: left, right, top, bottom,front and back.

-boundary

-noboundary

This option defines a domain named boundary that groups all sides. By default, both sides and the whole boundary are defined as domains:

        mkgeo_grid -t 10 > square.geo
       geo square.geo
        mkgeo_grid -t 10 -nosides > square.geo
       geo square.geo
        mkgeo_grid -t 10 -noboundary > square.geo
       geo square.geo
        mkgeo_grid -t 10 -noboundary -nosides > square.geo
       geo square.geo

REGIONS

-region

-noregion

The whole domain is splitted into two subdomains: east and west, This option is used for testing computations with subdomains (e.g. transmission problem; see the user manual).

        mkgeo_grid -t 10 -region | geo -

CORNERS

-corner

-nocorner

The corners (four in 2D and eight in 3D) are defined as OD-domains. This could be usefull for some special boundary conditions.

        mkgeo_grid -t 10 -corner | geo -
        mkgeo_grid -T  5 -corner | geo -

COORDINATE SYSTEM OPTION

Most of rheolef codes are coordinate-system independant. The coordinate system is specified in the geometry file `.geo'.

-zr
-rz: the 2d mesh is axisymmetric: zr (resp. rz) stands when the symmetry is related to the first (resp. second) coordinate.