[Archive] Draw the satellite

SPIS
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Message by Aleksandra Chudnovskaya:
How can I draw the satellite by myself and give to it necessary physics characteristics, to use it for modelling later?
Thank You,
Aleksandra

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Message by Benoit Thiebault:
Dear Aleksandra,
Welcome on SPIS forum.
If you have downloaded SPIS 3.7RC09 (\http://dev.spis.org/projects/spine/home/spis/software/download/Spis3_7RC09_tgz), the documentation is included.
To access it, when you launch SPIS, go to the Help>Online Help menu. A web page should be displayed and list the different technical note. The one that you should look at is the TN01 : Spis User Manual. Section 2.5 deals with creating the spacecraft and setting its charateristics.
You can also create your spacecraft geometry outside SPIS using the GMSH (\http://www.geuz.org/gmsh/) Open Source software (provided with SPIS in the Thirdpart directory).
If you have problems with this procedure, do not hesitate to post your questions on the forum
Benoît
Artenum crew

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Message by Benoit Thiebault:
In GMSH user manual (provided in SPIS help main page : \http://www.geuz.org/gmsh/doc/texinfo/gmsh.pdf), you can find the definition of Gamma, Eta and Rho :

What is the signification of Rho, Eta and Gamma in Tools->Statistics?They measure the quality of the tetrahedra in a mesh:Gamma ~ inscribed\_radius / circumscribed\_radiusEta ~ volume^(2/3) / sum\_edge\_length^2Rho ~ min\_edge\_length / max\_edge\_lengthFor the exact definitions, see Geo/MElement.cpp. The graphs plot the number of elements vs the quality measure.
There is also a very detailed tutorial that you can find in your Doc directory : SPIS/Doc/DocSpisUI/Other/SPIS-Gmsh\_UT-GS031006.pdf Pos files are postprocessing files generated by GMSH. You don't need them. You should use GMSH only to define your geometry file (.geo file), and potentially to check the mesh generation. The rest is performed within SPIS. Once you have finished your geometry design with gmsh, you should follow the tutorial. To summarize, the esaiest way is to follow the toolbar buttons, starting by the CAD tool caller : 1) Call the CAD tool 2) Click the "add file" button to add your newly created geo file 3) Select your file and click the "set as main" button 4) Click the "update project" button 5) Click the "load geometry" and the "load properties button" 6) Open the material editor and edit your material, plasma and boundary properties (see tutorial for details) 7) Click all the other buttons in the same order (from left to right) until you reach the solver button. To know if a task is completed correctly, open the console, marked by a small triangle on the bottom left corner and watch the logs. When a task is over, it should display "Task XXX just terminate" Good luck Benoît
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Message by Aleksandra Chudnovskaya:
Thank You very much!
But I still have a problem…
Of course, I’ve read \http://www.geuz.org/gmsh/doc/texinfo/gmsh.pdf before have addressed to you. And it was not helpful, because there was a FAQ only about geometry.
So, I’ve repeatead all my actions with the opened console and found an error: “ERROR100: Data inconsistency! Please clean all existing DataFields and check your groups settings and propeties definitions”.I set all default propeties, that I found in the user manual. And now I really don’t know what to do… Help!..

Aleksandra

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Message by Benoit Thiebault:
This error message means that you did’nt configure correctly the material properties.
How many groups (i.e. physical surfaces in your geo file) do you have ? For a basic spacecraft (with only one material property), you should have two physical surfaces (one for the external boundary and one for the spacecraft geometry) and one physical volume (the plasma in between).
In the material editor, you should set :

  • the first surface group (depending in what order they were created in gmsh) to ITO (or whatever material property you need), spacecraft ground and Spacecraft default for the material/ElectNode/Plasma combo boxes
  • the second surface group to none, none, boundary default
  • the volume group to none, none, plasma model in volume, default
  • The point and curve groups should still be at none for all caracterictics
When you have this kind of message, you should clean the data in memory before trying again. The simplest way is to shut the app down and start again. Otherwise, you can go in the databus menu and choose clean data bus. Then in the sharedData tab, select all and clean. Benoît
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Message by Aleksandra Chudnovskaya:
Hi! It’s me again.
Thank you very much for your reply! It was very helpful!
I created 2 cubes: one is internal and one is external. So, I had 2 physical surfaces (one for small cube and one for big cube) and one geometry volume between these cubes. I loaded GEOM and default propeties for materials (as you wrote). Then called the mesher, converted the GEOM (CAD) groups, called the Global Parameters editor and pushed there “save and quit”. Then I pushed the button “Convert data from UI to NUM data structure”. And it was successful. Then I pushed the botton “solver”. There I chose “External job”, Simulation name: Sim, Run Id: 1. And set the flag at “Launch the daemon now”. The program printed:
external task
Ok
OK
SimulationDeamon
J:\SPIS\Sasha temp\spisSimulationDeamonForSimOnRun1.py
J:\SPIS\spis3_6\ThirdPart\Jython\jython-2.1\spis_tasks_guiOSX.sh -b /Users/juju\spisSimulationDeamonForSimOnRun1.py
Impossible to launch the job.
Then I repeated my past action, but didn’t set a flag. I called the “DataField manager” and exported some data to VTK. And when I called the 2D Viewer there was no data.
So, I think, I do something wrong again. And I hope, you’ll help me…
Thank you,
Aleksandra.

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Message by Aleksandra Chudnovskaya:
I’ve downloaded an earlier version of SPIS and these problems have solved… but now I have some new questions…

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Message by Benoit Thiebault:
Indeed, there seems to be a bug in the external job function in this version of SPIS. Our developers are working on it. The simplest approach is to use the “internal daemon” for now.