CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > ANSYS Meshing & Geometry

[ICEM] Multiblock plot3d

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   March 31, 2013, 18:41
Default Multiblock plot3d
  #1
New Member
 
Papis
Join Date: Dec 2010
Posts: 25
Rep Power: 6
papis is on a distinguished road
Hi to all,

I am opening an new thread about this issue I have, with a plot3d mesh.
I have a grid of wind turbine blade of approximately ~5million nodes.The grid is in plot3d format and is split in 144 blocks with no Iblank arrays.

I use ICEM CFD in order to open the mesh apply boundary conditions/minor changes and export it in the format that I want.

When the mesh is imported ICEM asks if I want to recompute mesh topology or use basic topology where it's domain it's unattached to the other.

At first i chose recompute mesh topology.What ICEM did was to remove the double interblock boundaries.The way the plot3d mesh is structured each x,y,z coordinate is repeated at interblock boundaries and thus double nodes/lines/shells are created pointing to the same x,y,z coordinates.

By recomputing mesh topology the double nodes/lines/shells were removed.However the interblock boundaries remained(I will explain later about that) and also the check mesh utility identified problematic edges at interblock boundaries.

By using the basic topology where each domain is assumed unattached to another the check mesh utility showed no problems.However at each interblock boundary I had double nodes shells etc..

My main issue about ICEM recognizing the inter-domain boundaries as real boundaries is that I have to create a part (interior/wake bc) which is not easy/error-proof when you have 144 blocks and mesh with first-layer 1e-06 with 5 million nodes.I need a systematic way of doing that or way to make ICEM understand that the domains should be merged thus leaving only the real boundary shells(which I assume is the correct way).

Another thing that I tried is splitting the mesh to 144 single plot3d grids.I thought if I load them one by one maybe something would change.Indeed when I loaded the second block ICEM asked if it should merge the mesh or replace it.I chose merge and wow the interblock boundary disappeared without asking anything about topology. However even this workaround was not plausible because the 5th block didn't have any actual connection with the 4th and when I loaded the 5th everything else disappeared (also I didn't liked the idea of loading 144 files by hand)...(I hope i didn't confuse you)

Does anybody have an idea of how to address this problem?I think I am missing something because identifying domains that are attached and merging them should be a trivial task for ICEM (or not?).

Also I would like to point out that because the mesh is imported no Geometry is present.

Any idea would be appreciated


Thank you very much for your time

I have attached a picture of the mesh.the lines show the interblock boundaries and the shells are the the surface bound cells.
Attached Images
File Type: jpg LINES.jpg (94.5 KB, 20 views)
File Type: jpg SHELLS.jpg (98.2 KB, 21 views)
papis is offline   Reply With Quote

Old   July 16, 2014, 11:32
Default
  #2
New Member
 
Join Date: Jan 2014
Posts: 1
Rep Power: 0
Bretert is on a distinguished road
Dear Papis,

have you already solved your problem? I have met the same problem and I am wondering if you have found a solution.
Bretert is offline   Reply With Quote

Old   July 16, 2014, 11:42
Default
  #3
New Member
 
Papis
Join Date: Dec 2010
Posts: 25
Rep Power: 6
papis is on a distinguished road
Hi Bretert

No I haven't found something that makes icem disregard the double nodes edges.However, what I did was to create a different part for the interblock boundaries and apply wake-like boundary conditions to that part(wake like in the sense as in 2D structured grids double sided wake line).

What helped me a lot in creating these parts(because if you have lot's of blocks it will be problematic) is the hotkeys "l","k","r" . When creating a part you select the first element and then move using those hotkeys since using the mouse is impossible at least at the beginning. "l" select elements up to an angle,"k" selects element by directions and "r" up to a curve.

Another thing that I found is that gridgen by pointwise can actually merge those different domains however I don't think that's a proper solution since it doesn't apply to ICEM.

Good luck
papis is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
PLOT3D IBLANK data ufocfd ParaView 0 November 13, 2012 07:26
[ICEM] Plot3D mesh import problem drbones ANSYS Meshing & Geometry 1 January 27, 2012 16:18
import plot3d multiblock grid to icem-cfd autoflly Main CFD Forum 2 May 11, 2006 15:47
PLOT3D Equations Alfonso Villanueva Main CFD Forum 1 June 23, 2005 16:51
Gambit - PLOT3D Danny Tan FLUENT 0 December 26, 2001 01:43


All times are GMT -4. The time now is 07:10.