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-   -   Helical wire wrapped around cylinder blocking strategy in ICEM (http://www.cfd-online.com/Forums/main/100082-helical-wire-wrapped-around-cylinder-blocking-strategy-icem.html)

wingcollide April 19, 2012 16:25

Helical wire wrapped around cylinder blocking strategy in ICEM
 
2 Attachment(s)
Hello everyone

I have joined recently a heat transfer project where it is difficult to take certain measurements and so we will try to run numerical simulations to better understand the temperature field as well as the turbulence distribution of the flow.
I have used ICEM in the past for meshing different simple geometries with tetrahedras, and because I am somewhat familiar with it I chose it as my meshing tool. My supervisor wants a structured mesh, however I have run into different obstacles when trying to obtain one.
First I have blocked the helical wire extruding one face along the central curve, and twisting it with a specific angle to accommodate the helical pitch. I have obtained a premesh for the entire volume of the wire(although only the surface in volume Body was needed) and transformed it into an unstructured mesh. I have attached my geometry and the mesh for the wire wrap.
Then I tried to make a surface mesh for the surface around which the wire is wrapped. Unfortunately this resulted in a mesh with elements that didn't line up with the ones of the wire, and also with elements in the volume that should be empty.
The last step I would have followed was to create inflation layers from the surface mesh of the inner cylinder wrapped with the wire to the outer surface surrounding it.

I was wondering if anyone has any suggestion on a blocking strategy for this geometry.

Thanks for any ideas

cnsidero April 20, 2012 09:54

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wingcollide a while ago I was working on the same problem you are asking about. I never figured out how to create the block topology for such a configuration. I ended up settling on a hybrid configuration whereby I created a structured extrusion around the cylinder and helical wire (for the BL resolution) and unstructured mesh in between. In the attached images you can see a close up of the mesh around one cylinder and the entire setup.

If you manage to figure out how to make it all structured, let me know.

wingcollide April 20, 2012 13:12

cnsidero, thanks a lot for your reply, the mesh in the close up image looks very good.
I will probably end up doing something similar although I still hope I will find a solution for a structured mesh.
I will let you know if I find one.

cdf_user April 21, 2012 02:33

Quote:

Originally Posted by cnsidero (Post 355844)
wingcollide a while ago I was working on the same problem you are asking about. I never figured out how to create the block topology for such a configuration. I ended up settling on a hybrid configuration whereby I created a structured extrusion around the cylinder and helical wire (for the BL resolution) and unstructured mesh in between. In the attached images you can see a close up of the mesh around one cylinder and the entire setup.

If you manage to figure out how to make it all structured, let me know.

I have been working with ICEM CFD for a while but I am still not able to figure to create a mesh gradient such that mesh is finer near the boundaries and coarser in the middle. Could you please explain how you created the mesh gradient ? I think it has something to do with blocking where you split the domain into blocks and have finer mesh in some blocks and coarser in others. But it hasnt worked out for me because at the end I have a problem of unstructured mesh that somehow needs to be converted to structured mesh. I dont know what the terms structured and unstructured mesh mean?

huisenanhai December 25, 2013 02:13

DO you find a solution for a structured mesh in this geometry using ICEM?
 
Quote:

Originally Posted by wingcollide (Post 355880)
cnsidero, thanks a lot for your reply, the mesh in the close up image looks very good.
I will probably end up doing something similar although I still hope I will find a solution for a structured mesh.
I will let you know if I find one.

Hi , DO you find a solution for a structured mesh in this geometry using ICEM?
I know in India , N. Govindha Rasu Building structured mesh of this geometry using GridZ tools. You can see from the paper "simulaneous development of flow and temperature fields in wire-wrapped fuel pin bundles of sodium cooled fast reactor".

cnsidero December 25, 2013 13:15

Quote:

Originally Posted by huisenanhai (Post 467579)
Hi , DO you find a solution for a structured mesh in this geometry using ICEM?
I know in India , N. Govindha Rasu Building structured mesh of this geometry using GridZ tools. You can see from the paper "simulaneous development of flow and temperature fields in wire-wrapped fuel pin bundles of sodium cooled fast reactor".

Thanks for the reply. Unfortunately I don't have access to the journal paper and the images are too small to see any detail in the publicly available one. Do you have the paper or some better images of the mesh from the paper?

huisenanhai December 25, 2013 20:32

please leave you email, I'll send the paper to you !


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