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-   -   [ICEM] Hybrid meshing close to surface (http://www.cfd-online.com/Forums/ansys-meshing/107004-hybrid-meshing-close-surface.html)

k.vimalakanthan September 14, 2012 12:54

Hybrid meshing close to surface
 
1 Attachment(s)
Hi guys,

I have been able to create hybrid meshes using ICEM with the merge nodes > merge meshes function, for meshes that have large elements. But when I try to merge meshes with boundary layer and prism layer ICEM just freezes..

I was wondering if anyone have successfully created a hybrid mesh that includes a boundary layer on both sides i.e close to the surface. I'm trying to use very small initial height in the order of 1e-05. The tetra side of the mesh contains a prism layer and the hexa side contains O-grid boundary layer mesh. Both meshes have same amount of nodes on the curves/edges with similar distribution.

It's clearly been done using the meshing software Centaur (see attachment). I'm basically trying to recreate this mesh in ICEM.

Could anyone please tell if it is even possible to attempt such a thing in ICEM?

Any light on this matter is greatly appreciated :)
Kind regards,
Kishore

PSYMN September 15, 2012 21:05

There is a tutorial about this (HVAC tutorial).

Basically, the ICEM CFD Merge meshes option only works if one side is all tetra... Then you need to add the prisms later...

It can be done, but it is a bit of a hassle. I know they are working on making it much easier, but that will be for a later version.

I have never seen it create anything like in your picture. But it would be pretty easy to get it to create a straight hexa mesh thru that region. Actually, I can't really understand why you even want to do that :confused:

k.vimalakanthan September 15, 2012 21:49

Firstly thank you very much for the much appreciated reply simon :D

Regards to the tutorial "HVAC tutorial", could you please send me a link for this tutorial as I could not find it on google or in the icem tutorial folder :(
Maybe you could please send it to my email: k.vimalakanthan@cranfield.ac.uk

From what I understand I have compiled the steps to create a boundary layer for a hybrid mesh. Could you please confirm if this is the correct approach for such a mesh:

1. Create Hex mesh with the initial node height (set on the blocking edges) being the maximum boundary layer height

2. Create tri mesh with the initial node height (set on the side prism side curves) being the maximum boundary layer height

3. Merge the intersection surface using merge nodes > merge meshes function

4. Generate Prism layers (both bottom surface from tri and hex are ticked for the prism layers)

Because I do remember trying such approach and failing but I will give it a try again. I think the tutorial you mention will help me a lot.

I did come across some other threads describing different approaches for this problem:
1. Using the "Existing quad layers" option to generate the prism layers - tried and failed to succeed
2. Splitting the prism after merging nodes- don't really understand this method :(
Could you please suggest if I should consider any of these above methods?

Regards to the picture, Im also not sure why they have computed such a mesh. I was able to generate such a surface mesh when I converted Hex elements to tri. I suspect that they have done this so the tri surface nodes aligns well with nodes from the hex surface at the hybrid intersection, thus merging nodes becomes easy. Unfortunately I can only speculate.

Kind regards,
Kishore

k.vimalakanthan September 15, 2012 22:01

Forgot to mention that I'm also interested in reviewing on of your pdf named "Tips of ICEM 2008". Could you please send this one too.

Thank you :)
Kind regards,
Kishore

PSYMN September 20, 2012 16:42

I sent the 2010 one instead... I guess I am way overdue on an update for that also. :o

raghav September 27, 2012 08:04

Reg. Tips of ICEM 20101
 
Hi Simon,

Can u also share the same with me??

Regards,

Raghav M S
seetharamu.raghav@gmail.com

PSYMN September 27, 2012 08:13

@raghav...

Done.

BrolY September 27, 2012 09:01

Hi Simon,

Could you also send it to me please ?

brolyrahmal@hotmail.com

Maybe you could upload it to a FTP, that would be easier for you !

raghav September 27, 2012 09:44

Thanks a lot:)

PSYMN September 27, 2012 13:32

ANSYS changed the policy and took down the old ftp site... I could post it in the customer portal, but a lot of you have trouble accessing that...

BrolY September 28, 2012 03:27

Thank you Simon !

macfly October 6, 2012 17:17

@ Simon,

My turn please! Can't we share those pdf files on google docs or something?

I'm having a hard time trying to merge a complex fluid region mesh with a simple solid region mesh.

f.gregoire.3@gmail.ca

Thanks a lot in advance,
Regards,
François

nkme2007 October 10, 2012 05:57

Hello All,

I want to do analysis of heat transfer from water flowing through pipes submerged inside concrete. I am modelling in GAMBIT and wish to analyse it on Ansys FLUENT.

Can anybody help me out, how to model and simulate?

Does any tutorials exist?

k.vimalakanthan October 15, 2012 12:23

ICEMCFD Tips&Tricks 2010 pfd
 
ICEMCFD Tips&Tricks 2010 document

Quote:

Originally Posted by PSYMN (Post 386293)
I got so many requests for this ICEMCFD Tips&Tricks 2010 pfd that I figured out how to share it over google docs...

https://docs.google.com/open?id=0ByI...nBqTXBQT3pQMjQ

Yes, it is well overdue for an update, but it can still help many of you.

Best regards,

Simon


macfly October 18, 2012 23:20

Thanks Kisorthman


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