[ICEM] Creating 3D mesh in ICEM with defined boundaries

martyn88 · August 27, 2012, 23:09

Hi everyone,

I am having trouble creating a 3d mesh for a LES simulation I am doing for a supersonic free jet. I have created a 2D geometry and structured mesh in ansys (find attached) and am quite happy with it. Being LES, I need a 3d mesh, so I now need to revolve it 45 degrees to make a 1/8th section. I am running the simulation using OpenFOAM but doing the meshing and geometry in ansys. However I need to define the boundaries in ansys so that when I export it to OpenFOAM it recognises them and BC's can be applied.

I need to define an inlet surface, the nozzle wall surface, and the freestream surface. Also I need to set up a cyclic pair on each side surface (periodic in the circumferential direction).

I exported the 2d mesh from ansys in .msh format then imported it to ICEM and extruded it to 3D (also attached) and it looks great, however I need to redefine the boundaries. Is there any way of defining boundaries at this stage? Or do I have to define them on the geometry?

I'm super confused, what is the best way to do this!!!!!!

2d geometry.JPG

2d mesh.jpg

3d ICEM mesh.jpg

diamondx · August 28, 2012, 09:09

If i'am not wrong, Boundaries has to be defined in geometry, then associated to the edge in a structured mesh. once the .msh is created, it's too late.

PSYMN · August 28, 2012, 09:46

It would have been easier to name the edges before you generated the initial mesh, but it is not too late. It is just a little more effort.

In the display tree, right click on parts to create a new part. Lets call the first one "INLET".

Then with only shell elements displayed, go over to that are of the model and select the shells you want to put into that part.

There are lots of selection tools to help you get just the ones you want. For instance, you could use a polygon (p) or a box, or your could select a single element on a face and floodfill to angle. You can even set the angle, but I think the default of 30 degrees should work fine in your case.

martyn88 · September 9, 2012, 11:43

Thanks for the help guys, I ended up using ansys mesher and defined the cyclic boundaries using fluent.

Cheers

samidabest · September 9, 2012, 16:42

( i make the 2d model of shell and tube heat exchanger and mesh it but when select heat exchanger model in fluent it give error that primary and auxiliary regions are not overlapping ..... so plz help me what i do .... i'm new to use ansys

August 27, 2012, 23:09	Creating 3D mesh in ICEM with defined boundaries	#1
martyn88 Member Hugh Ingham Join Date: Aug 2012 Posts: 35 Rep Power: 14	Hi everyone, I am having trouble creating a 3d mesh for a LES simulation I am doing for a supersonic free jet. I have created a 2D geometry and structured mesh in ansys (find attached) and am quite happy with it. Being LES, I need a 3d mesh, so I now need to revolve it 45 degrees to make a 1/8th section. I am running the simulation using OpenFOAM but doing the meshing and geometry in ansys. However I need to define the boundaries in ansys so that when I export it to OpenFOAM it recognises them and BC's can be applied. I need to define an inlet surface, the nozzle wall surface, and the freestream surface. Also I need to set up a cyclic pair on each side surface (periodic in the circumferential direction). I exported the 2d mesh from ansys in .msh format then imported it to ICEM and extruded it to 3D (also attached) and it looks great, however I need to redefine the boundaries. Is there any way of defining boundaries at this stage? Or do I have to define them on the geometry? I'm super confused, what is the best way to do this!!!!!! 2d geometry.JPG 2d mesh.jpg 3d ICEM mesh.jpg

August 28, 2012, 09:09		#2
diamondx Super Moderator Ghazlani M. Ali Join Date: May 2011 Location: Tokyo, Japan Posts: 1,385 Blog Entries: 23 Rep Power: 29	If i'am not wrong, Boundaries has to be defined in geometry, then associated to the edge in a structured mesh. once the .msh is created, it's too late. __________________ Regards, New to ICEM CFD, try this document --> https://goo.gl/KAOIwm Ali

August 28, 2012, 09:46		#3
PSYMN Senior Member Simon Pereira Join Date: Mar 2009 Location: Ann Arbor, MI Posts: 2,663 Blog Entries: 1 Rep Power: 47	It would have been easier to name the edges before you generated the initial mesh, but it is not too late. It is just a little more effort. In the display tree, right click on parts to create a new part. Lets call the first one "INLET". Then with only shell elements displayed, go over to that are of the model and select the shells you want to put into that part. There are lots of selection tools to help you get just the ones you want. For instance, you could use a polygon (p) or a box, or your could select a single element on a face and floodfill to angle. You can even set the angle, but I think the default of 30 degrees should work fine in your case. Far and diamondx like this. __________________ ----------------------------------------- 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

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September 9, 2012, 11:43		#4
martyn88 Member Hugh Ingham Join Date: Aug 2012 Posts: 35 Rep Power: 14	Thanks for the help guys, I ended up using ansys mesher and defined the cyclic boundaries using fluent. Cheers

September 9, 2012, 16:42		#5
samidabest New Member samiullah Join Date: Aug 2012 Posts: 21 Rep Power: 14	( i make the 2d model of shell and tube heat exchanger and mesh it but when select heat exchanger model in fluent it give error that primary and auxiliary regions are not overlapping ..... so plz help me what i do .... i'm new to use ansys