Volume mesh with hole boundaries

SPIS
1

Hello all,

I am exploring the SPIS and program’s user interface recently and I have been struggling with such issue recently. I did create a scenario in order to simulate space plasma environment around a generic basic spacecraft volume (box).

However, I could not manage to perform a boolean operation to calculate the volumetric mesh around the surface of the box. From the user interface of GMSH, I choose to create a volume with the outer boundary and then select the spacecraft volume (box) as a hole boundary. However, each time it ends up with creating a mesh with whole outer boundary without a hole (box) inside of it.

I have tried to do the same approach with boolean operations and I got the same result as before by adding the codes below to the .geo file:
SetFactory(“OpenCASCADE”);
BooleanDifference(20060) = { 20037; Delete; }{ 20038; Delete; };
and I get a syntax error by using ", (, ) characters.

How can I solve the issue?

I am currently using the last version of SPIS-Propulsion 6.0.4 with regular embedded GMSH version.

Best Regards

2

Hello again,

I did initialize the simulation by meshing with hole boundary by the synthax below;
Surface Loop(20052) = {20038, 20039, 20040, 20041, 20042, 20043};
Surface Loop(20053) = {20044, 20045, 20046, 20047, 20048, 20049};
Volume(20055) = {20052, 20053};

Physical Surface(50000) = {20038, 20039, 20040, 20041, 20042, 20043}; //internal boundary
Physical Surface(50001) = {20044, 20045, 20046, 20047, 20048, 20049}; //external boundary

Physical Volume(50001) = {20055};

Best Regards

3

Hello Agozutok,

In SPIS version 5.2.4, there is an example of a simple Gmsh geo sphere in a box. I think it can be helpful for you.

First, download SPIS 5.2.4 (the choice of the OS does not matter here), for example:

https://www.spis.org/get/software/spis/surface/5.2.4/Spis-5.2.4-linux64b.zip

Then unzip it. In the unzip SPIS package, you will find the Gmsh .geo file in the path below:

/Spis-5.2.4/data/SphereLowResolution.spis5/DefaultStudy/Preprocessing/Geometry/GeometricalSystem/cad_sav.geo

I hope it will help you,

Regards,

Benjamin

1 Like
4

Hello Ruard,

Thanks for the recommendation, I will definitely check the this example *.geo file too.

Best Regards