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Gmsh Functions 1

Posted January 21, 2013 at 07:18 by Hisham (Notes for OpenFOAM!)

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:

Code:

Include "Functions.geo" ;

The Functions.geo file is a file that has some function...

Hisham

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Convergence

Posted January 16, 2013 at 15:45 by arashsk

Quote:

Originally Posted by Centurion2011

I see all kind of mistakes on these forums when dealing with convergence, so I will give brief review of methods...

At convergence, the following should be satisfied:

All discrete conservation equations (momentum, energy, etc.) are obeyed in all cells to a specified tolerance OR the solution no longer changes with subsequent iterations.
Overall mass, momentum, energy, and scalar balances are achieved.
Monitoring convergence using residual history:
Generally, a decrease

...

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Transient Temperature Profile

Posted January 16, 2013 at 10:04 by diamondx

UDF for a transient temperature profile

Quote:

Originally Posted by alven299

Have figured it out. Here is the script, hope it might be of help to others:

#include "udf.h"

DEFINE_PROFILE(inlet_temperature,t,i)
{
real x[ND_ND];
real time;
face_t f;

begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
time=CURRENT_TIME;
if(time<40)
F_PROFILE(f,t,i)=300;

else

F_PROFILE(f,t,i)=340;

...

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Exporting blocking/mesh for a similar geometry By simon

Posted January 6, 2013 at 19:23 by diamondx

During import, you can also associate the new geometry file with the old tetin file so all the family sizes, etc. are preserved... This is an option near the top of the import DEZ.

Then load the old blocking file and update the associations.

If they don't all auto associate properly, you can use the interactive controls to adjust things...

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scale factor By simon

Posted January 6, 2013 at 19:17 by diamondx

Scale factor lets you adjust all the sizes in the model at once...

By default, you should probably leave it as 1, which means that all the other sizes could be taken at face value.

Then if you want to make the model 20% coarser, you can come back and set the scale factor as 1.2. Get it?

Scale Factor times Max Element size gives you the largest element in your model. For Octree, this is the size of the initial subdivision when Octree is first initialized....

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