In this blog, quick reference notes about OpenFOAM are posted in a form of a summary to address a specific topic per post.
Gmsh Functions 1
Posted January 21, 2013 at 07:18 by Hisham
Tags gmsh
Gmsh is a powerful mesh generator. One of its strength points is the use of both scripting and GUI functionality. Scripting has two neat features: Function : lets one define a function and call it several times. Include : lets one include other scripts into the geometry file script.
Assume we have a Mesh.geo file that we have for the geometry. You can start off by:
The Functions.geo file is a file that has some function definitions. In this post, I wrote some easy functions. Hope to extend them in future posts (any suggestions are welcome)
The Functions.geo file:
Hisham El Safti
Assume we have a Mesh.geo file that we have for the geometry. You can start off by:
Code:
Include "Functions.geo" ;
The Functions.geo file:
Code:
Function Quadrangle
/*
* X, Y, Z, lc
* point dX dY
* 1 0 0
* 2 dX2 dY2
* 3 dX3 dY3
* 4 dX4 dY4
*
* Transfinite:
* Horizontal: N_H
* Vertical: N_V
*/
p1 = newp; Point(p1) = {X,Y,Z,lc};
p2 = newp; Point(p2) = {X+dX2,Y+dY2,Z,lc};
p3 = newp; Point(p3) = {X+dX3,Y+dY3,Z,lc};
p4 = newp; Point(p4) = {X+dX4,Y+dY4,Z,lc};
l1= newl; Line(l1) = {p1, p2} ;
l2= newl; Line(l2) = {p2, p3} ;
l3= newl; Line(l3) = {p3, p4} ;
l4= newl; Line(l4) = {p4, p1} ;
Transfinite Line {l1, l3} = N_H;
Transfinite Line {l2, l4} = N_V;
ll1 = newll; Line Loop(ll1) = {l1, l2, l3, l4};
pl1 = news;
Plane Surface (pl1) = {ll1};
Transfinite Surface {pl1};
Recombine Surface {pl1};
Return
Function Rectangle
dX3=dX2;
dX4=0;
dY2=0;
dY4=dY3;
Call Quadrangle ;
Return
Function Square
dY3=dX2;
N_V = N_H;
Call Rectangle ;
Return
Function ExtrudeFunc
myExt[]=Extrude {ExX, ExY, ExZ}{
Surface{pl1};
Layers{ExLayers};
Recombine;
};
Return
Function Cuboid
Call Quadrangle;
Call ExtrudeFunc;
Return
Function RectCuboid
Call Rectangle;
Call ExtrudeFunc;
Return
Function Cube
Call Square;
ExLayers = N_H;
ExZ=dX2;
Call ExtrudeFunc;
Return
/******************************************************************************\
Define/Change Parameters Before Calling Functions
\******************************************************************************/
lc = 0.1;
X = 0;
Y = 0;
Z = 0;
dX2 = 1;
dX3 = 0.9;
dX4= 0.4;
dY2= 0.05;
dY3= 0.2;
dY4= 0.18;
N_V=5;
N_H=20;
//Call quadrangle ;
//Call Rectangle ;
//Call Square ;
ExX = 0;
ExY = 0;
ExZ = 2;
ExLayers = 30;
//Call Cube;
//Call Cuboid;
//Call RectCuboid;
// Automatically Assign Physical Volume to the Extrude
// Physical Volume ("myVolName") = {myExt[1]};
// myExt[0] is the ID of the opposite new surface
// Physical Surfaces are to be defined manually for the whole geometry
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