# [Gmsh] Pseudo 2-D unstructured Mesh

Emanuele T. nuovodna at gmail.com
Tue Jun 8 18:46:44 CEST 2010

```I solved using different values from z coordinates and lc.
This .geo file works
Point (1) = {0, 0, 0, 0.05};
Point (2) = {3.2196, 0, 0, 0.05};
Point (3) = {3.2196, 1.8, 0, 0.05};
Point (8) = {0, 1.8, 0, 0.05};
Point (9) = {1.2, 0, 0, 0.05};
Point (12) = {1.2, 0.6, 0, 0.05};
Point (13) = {0, 0.6, 0, 0.05};
Line (1) = {8, 3};
Line (2) = {3, 2};
Line (3) = {2, 9};
Line (4) = {9, 12};
Line (5) = {12, 13};
Line (6) = {13, 1};
Line (7) = {1, 9};
Line (8) = {13, 8};
Line Loop (10) = {1, 2, 3, 4, 5, 8};
Plane Surface (10) = {10};
Line Loop (12) = {5, 6, 7, 4};
Plane Surface (12) = {12};
e1[] = Extrude {0, 0, 0.1} {Surface{10,12}; Layers{1}; Recombine;};
Physical Surface(67) = {23};
Physical Surface(68) = {43, 57};
Physical Surface(69) = {61, 31};
Physical Surface(70) = {27};
Physical Volume(72) = {1, 2};

A key role is covered by Layers{1} in Extrude function

2010/6/8 Emanuele T. <nuovodna at gmail.com>

> Hi, i d like to create a pseduo 2-D mesh but i have problems. If i use
> characteristic length and z coordinates equal to 0.1 it works (i m using
> gmshToFoam to import in OpenFOAM and solve a 2-d case using a 3-d mesh with
> 1 cell in z direction). I'd like to make a mesh finer and i have set lc and
> z coordinates to 0.04. Unfortunately in this way i don't obtain a pseudo 2-D
> mesh but a full 3-D mesh (more than one cell in z direction). How can i
> solve?? How can i obtain a fine mesh with low lc and 1 single cell in z
> direction?