[ANSYS Meshing] Coordinate system Import to Fluent

superduke1200 · December 6, 2018, 08:28

I am implementing a fluid analysis on cerebral aneurysms and it is obligatory to apply the origin of my coordinate system at the inlet of the aneurysm.

I use Ansys Mechanical for the meshing of my geometry which comes with a pre-applied Global coordinate system. I am able to create a new coordinate system at the inlet of the aneurysm ( attached image 33 ), but my query is as follows;

how can I use my 'Custom' coordinate system applied on the Inlet as the default one instead of the global?

You see, after I have created my mesh, I am using Ansys Fluent and I must use the 'Custom' coordinate system in order to have accurate results when I calculate coordinate related factors. Fluent uses the Global one, created by default in Mechanical.

I have already tried the 'Translate Mesh' option ( attached image 44) based on the offsets derived from Mechanical, but it is not enough, because an alignment of the axes-Mesh is required. And the 'rotate mesh' option is not adequate to create a correlation from the data provided in Mechanical.

I guess that's it. I hope you will find time some day and share your thoughts with me.

khuti99 · December 13, 2018, 00:01

I think the best way would be moving the geometry so that the Global CS is where you need it and then meshing and importing it to Fluent.
If you work with ANSYS Workbench, there is a good chance that the mesh and the Fluent model will update automatically.

superduke1200 · December 13, 2018, 04:21

Quote:

Originally Posted by khuti99

I think the best way would be moving the geometry so that the Global CS is where you need it and then meshing and importing it to Fluent.
If you work with ANSYS Workbench, there is a good chance that the mesh and the Fluent model will update automatically.

How would you suggest that I move the geometry? It is a STEP file which I can open in DesignModeler. You can create a new 'plane' which is like creating a new coordinate system.

But the meshing should be done in Mechanical and then exported to Fluent.

I have most likely found out that there is no immediate way to import a coordinate system from Mechanical to FLUENT

khuti99 · December 14, 2018, 08:18

There is an old saying among my people: "If the mountain does not come towards Muhammad, Muhammad will come to the mountain"

)

Move your geometry in a way that the global origin is at the inlet (or however you need it) and adjust the angular position with rotation/s.

This way the global CS will satisfy the needs of your analysis.

Regards.

superduke1200 · December 16, 2018, 03:41

I am familiar with the rotate and translate options in Ansys Fluent. As I have said in my first post the data that I have are not adequate to apply any accurate rotation in Fluent.

Thanks for your input though.

If I apply a normal to inlet velocity, boundary condition in Fluent do you think that I will find any differences if I translate or rotate my mesh?

December 6, 2018, 08:28	Coordinate system Import to Fluent	#1
superduke1200 New Member Join Date: Dec 2018 Posts: 3 Rep Power: 7	I am implementing a fluid analysis on cerebral aneurysms and it is obligatory to apply the origin of my coordinate system at the inlet of the aneurysm. I use Ansys Mechanical for the meshing of my geometry which comes with a pre-applied Global coordinate system. I am able to create a new coordinate system at the inlet of the aneurysm ( attached image 33 ), but my query is as follows; how can I use my 'Custom' coordinate system applied on the Inlet as the default one instead of the global? You see, after I have created my mesh, I am using Ansys Fluent and I must use the 'Custom' coordinate system in order to have accurate results when I calculate coordinate related factors. Fluent uses the Global one, created by default in Mechanical. I have already tried the 'Translate Mesh' option ( attached image 44) based on the offsets derived from Mechanical, but it is not enough, because an alignment of the axes-Mesh is required. And the 'rotate mesh' option is not adequate to create a correlation from the data provided in Mechanical. I guess that's it. I hope you will find time some day and share your thoughts with me.

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December 13, 2018, 00:01		#2
khuti99 New Member Join Date: Dec 2018 Posts: 4 Rep Power: 7	I think the best way would be moving the geometry so that the Global CS is where you need it and then meshing and importing it to Fluent. If you work with ANSYS Workbench, there is a good chance that the mesh and the Fluent model will update automatically.

December 14, 2018, 08:18		#4
khuti99 New Member Join Date: Dec 2018 Posts: 4 Rep Power: 7	There is an old saying among my people: "If the mountain does not come towards Muhammad, Muhammad will come to the mountain" ) Move your geometry in a way that the global origin is at the inlet (or however you need it) and adjust the angular position with rotation/s. This way the global CS will satisfy the needs of your analysis. Regards.

December 16, 2018, 03:41		#5
superduke1200 New Member Join Date: Dec 2018 Posts: 3 Rep Power: 7	I am familiar with the rotate and translate options in Ansys Fluent. As I have said in my first post the data that I have are not adequate to apply any accurate rotation in Fluent. Thanks for your input though. If I apply a normal to inlet velocity, boundary condition in Fluent do you think that I will find any differences if I translate or rotate my mesh?