CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   ANSYS Meshing & Geometry (http://www.cfd-online.com/Forums/ansys-meshing/)
-   -   [ICEM] Structured mesh on ship hull (http://www.cfd-online.com/Forums/ansys-meshing/73220-structured-mesh-ship-hull.html)

nuovodna March 2, 2010 10:01

Structured mesh on ship hull
 
Hi, i m trying to set up a 3d structured mesh against a ship hull but i have some errors. I make a box and inside this box there is hull. Then i created 3d block, separate the two material object (FLUID and HULL), associeted edges/vertex with points/edges of geometry, pre-mesh. Finally i compute 3d mesh (Hex dominant) but i have errors like this: "error orienting normals". Please can you give me some advices?? I m crashing my head on this mesh :(

The files are here

http://dl.dropbox.com/u/3617688/hull.zip

PSYMN March 3, 2010 10:20

Look at this post...

http://www.cfd-online.com/Forums/ans...-modeling.html

Basically, your model is similar except that it is the blocks ahead of your boat that need to be collapsed...

in other words, think of your boat as an airfoil with a collapsed leading edge...

Viewing just from the top split on either side of the boat, then ahead and behind. Then split one thru the boat from side to side. Then collapse the block ahead of the boat...

Then continue on to split from the side view for the top, bottom, water level, etc.

nuovodna March 4, 2010 07:18

Thanks for your reply. I have a single box around my ship (the others box, water etc.. , are separated). Can i adapt this box to my ship geometrical entities?? Or i have to split this box and make different mini-box to associate at single parts of ship (upper surface, right surface, leading surface, left surface, trailing surface) ??


When i try to compute Hex Mesh it returns me 80% done but before this it gives me an error

"error orienting normals, perhaps there is more than one region"

PSYMN March 4, 2010 10:51

The mesh doesn't care about what it above or below the water line... your solver might though. You certainly don't need to break up the geometry, but that may help to give you some curves to hang on to. usually what I see is at least a split for the approximate water level so you can refine the mesh near that split and get better resolution of the location of the computed water surface. You can make that "water level" index "level" by setting the location of all the verts to have the same X, Y or Z coordinate.

The error message may be complaining about something else... Not sure what. Did you put the volume of the boat into a different part or is it a zero thickness hull?

nuovodna March 4, 2010 11:19

It's a zero thickness hull. I create two different Body and associated the block around the ship to HULL body previously defined. Then i associated the block edge and vertex to hull geometrical entities. Pre-Mesh : no problem. Compute 3-d Hex Mesh : surface mesh completely done, volume mesh fails

PS I tried to set up an half ship mesh but i have another problem
{expecting 2 shells on edge 361 20 found 4}
on 3D Hex Meshing

If you want i can upload my project files


All times are GMT -4. The time now is 05:35.