[ICEM] icem build topology problem

thais_b · January 9, 2012, 07:48

Hi!
I'm trying to build up a mesh around a 2d airfoil. I created the surface, the lines of the airfoil (it's a naca 0012 with trailing edge gap). However when i apply repair geometry> build diagnostic topology, icem creates some lines that make the mesh does not respect the airfoil boundaries. I've tried patch dependent and independent.
Anyone knows what is this?
Thanks in advance!

overview.jpg
closeup.jpg

Far · January 9, 2012, 08:08

pictures are not clear.

thais_b · January 9, 2012, 09:06

I'm sorry.
Thanks for you interest, Far!

The problem persists even if i increase the number of elements around the airfoil.
first.jpg

second.jpg

Far · January 9, 2012, 09:43

do you want to create unstructured mesh or interested in nice structured mesh with well resolved boundary layer?

thais_b · January 9, 2012, 10:40

Actually i'm trying to work with unstructured mesh + prism layers.
When Icem did not respect the airfoil, i used to correct it manually, editing the mesh. But the prism is constructed based on the built topology, so it does not work anymore.
I'm doing some research with icing accretions in airfoils, so unstructured mesh seems a good approach for that.
But some other ideas are welcome!
Thanks

PSYMN · January 10, 2012, 10:53

So you want a flat trailing edge?

Just make sure that your Build topo tolerance is smaller than your trailing edge thickness. Then you will get points on both the top and bottom of the trailing edge.

As for the second set of pics, it looks like the surface is not aligned with the curves, but that is just a display thing. If you want to clean it up, you can go into settings => Model and reduce the triangulation tolerance by an order of magnitude.

Best regards,

Simon

thais_b · January 19, 2012, 14:01

Thank you so much Simon.
It worked perfectly!

Thaís

January 9, 2012, 07:48	icem build topology problem	#1
thais_b New Member Join Date: Dec 2010 Posts: 10 Rep Power: 15	Hi! I'm trying to build up a mesh around a 2d airfoil. I created the surface, the lines of the airfoil (it's a naca 0012 with trailing edge gap). However when i apply repair geometry> build diagnostic topology, icem creates some lines that make the mesh does not respect the airfoil boundaries. I've tried patch dependent and independent. Anyone knows what is this? Thanks in advance! overview.jpg closeup.jpg

January 10, 2012, 10:53		#6
PSYMN Senior Member Simon Pereira Join Date: Mar 2009 Location: Ann Arbor, MI Posts: 2,663 Blog Entries: 1 Rep Power: 47	So you want a flat trailing edge? Just make sure that your Build topo tolerance is smaller than your trailing edge thickness. Then you will get points on both the top and bottom of the trailing edge. As for the second set of pics, it looks like the surface is not aligned with the curves, but that is just a display thing. If you want to clean it up, you can go into settings => Model and reduce the triangulation tolerance by an order of magnitude. Best regards, Simon __________________ ----------------------------------------- Please help guide development at ANSYS by filling in these surveys Public ANSYS ICEM CFD Users Survey This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)... CFD Online Users Survey

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Problem in running ICEM grid in Openfoam	Tarak	OpenFOAM	6	September 9, 2011 18:51
problem exporting from icem to fluent	jc_muaddib	FLUENT	1	June 16, 2010 05:16
[ICEM] Problem with ICEM generated Mesh	geothokar	ANSYS Meshing & Geometry	3	May 11, 2009 14:26
Icem Cfd To Cfx B.C. Problem	Kordou	CFX	4	July 17, 2008 13:49
build earth problem	stk	Phoenics	1	March 23, 2004 11:02

January 9, 2012, 08:08		#2
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	pictures are not clear.

January 9, 2012, 09:06		#3
thais_b New Member Join Date: Dec 2010 Posts: 10 Rep Power: 15	I'm sorry. Thanks for you interest, Far! The problem persists even if i increase the number of elements around the airfoil. first.jpg second.jpg

January 9, 2012, 09:43		#4
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	do you want to create unstructured mesh or interested in nice structured mesh with well resolved boundary layer?

January 9, 2012, 10:40		#5
thais_b New Member Join Date: Dec 2010 Posts: 10 Rep Power: 15	Actually i'm trying to work with unstructured mesh + prism layers. When Icem did not respect the airfoil, i used to correct it manually, editing the mesh. But the prism is constructed based on the built topology, so it does not work anymore. I'm doing some research with icing accretions in airfoils, so unstructured mesh seems a good approach for that. But some other ideas are welcome! Thanks

January 19, 2012, 14:01		#7
thais_b New Member Join Date: Dec 2010 Posts: 10 Rep Power: 15	Thank you so much Simon. It worked perfectly! Thaís