mkgeo_ugrid(1rheolef)

rheolef-7.0

mkgeo_ugrid(1rheolef)

NAME¶

mkgeo_ugrid -- build an unstructured mesh of a parallelotope, in 1d, 2d or 3d

SYNOPSIS¶

        mkgeo_ugrid options [n]

EXAMPLE¶

The following command build a triangle based 2d unstructured mesh of the unit square:

        mkgeo_ugrid -t 10 > square-10.geo
        geo -mayavi square-10.geo

or in one command line:

        mkgeo_ugrid -t 10 | geo -mayavi -

DESCRIPTION¶

This command is useful when testing programs on simple geometries. Invocation is similar to mkgeo_grid (see mkgeo_grid(1)). It calls gmsh as unstructured mesh generator. It avoid the preparation of an input file for a mesh generator. The optional n argument is an integer that specifies the subdivision in each direction. By default n=10. The mesh files goes on standard output.

The command supports all the possible element types: edges, triangles, rectangles, tetraedra, prisms and hexahedra. It supports also mixed 2D with triangles and quadrangles:

        mkgeo_ugrid -tq 10 | geo -mayavi -

and mixed 3D with tetraedra, prisms and/or hjexaedra:

        mkgeo_ugrid -TP  10 | geo -mayavi -
        mkgeo_ugrid -PH  10 | geo -mayavi -
        mkgeo_ugrid -TPH 10 | geo -mayavi -

ELEMENT TYPE OPTIONS¶

-e: 1d mesh using edges.
-t: 2d mesh using triangles.
-q: 2d mesh using quadrangles.
-tq: 2d mesh using both triangles and quadrangles.
-T: 3d mesh using tetraedra.
-P: 3d mesh using prisms.
-H: 3d mesh using hexahedra.
-TP
-PH
-TPH: 3d mesh using a mixt between tetraedra, prisms and/or 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_ugrid -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_ugrid -t 10 > square.geo
       geo square.geo
        mkgeo_ugrid -t 10 -nosides > square.geo
       geo square.geo
        mkgeo_ugrid -t 10 -noboundary > square.geo
       geo square.geo
        mkgeo_ugrid -t 10 -noboundary -nosides > square.geo
       geo square.geo

REGIONS¶

-region

-noregion

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

        mkgeo_ugrid -t 10 -region | geo -

CORNERS¶

-corner

-nocorner

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

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

THE MESH ORDER¶

-order int: The polynomial approximation mesh order, as defined by gmsh. This option enable a possible curved boundary, when applying a suitable nonlinear transformation to the mesh. Default is order=1.

OTHERS OPTIONS¶

-clean: clear temporary files (this is the default).
-noclean: does not clear temporary files.

COPYRIGHT¶

Copyright (C) 2000-2018 Pierre Saramito <Pierre.Saramito@imag.fr> GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.