[PSYMN]

Agreed... You should try ANSYS Meshing with patch conforming meshing if you want to get your Gambit Size function like behavior back.

[Far]

Dear Simon

Any plan to implement gambit tri pave and gambit size function in ICEM?

[PSYMN]

Sort of... It was implemented in Multizone. Multizone uses the Hexa framework, but when you have an unstructured block or paved face, it can use the gambit sizing function...

But I don't expect we will be hooking up the Gambit sizing function to the patch conforming mesher directly... Instead the direction is forward with ICEM CFD technology being hybridized with gambit (and other) technology in future products.

This is probably because users who want surface mesh to respect a sizing function can just use patch independent in ICEM CFD, which does respect the sizing function and also includes patch independence.

[sadjad.s]

Originally Posted by PSYMN

This is probably because users who want surface mesh to respect a sizing function can just use patch independent in ICEM CFD, which does respect the sizing function and also includes patch independence.

Hi Simon,
By "Size function" you mean Curvature/Proximity Based Refinement?

[PSYMN]

Originally Posted by sadjad.s

Hi Simon,
By "Size function" you mean Curvature/Proximity Based Refinement?

Yes, that is the ICEM CFD size function. It works with patch independent tetra and surface mesh.

[sadjad.s]

But it is different with Gambit Size Function except for name.

[PSYMN]

Yes, the ICEM CFD and Gambit Sizing functions are different code, independently developed, but for the same purpose.

TO me, the main difference is that the ICEM CFD tetra mesh is octree, and the mesh actually shows the sizing function directly. With Gambit, they actually run a size function controlled octree in the background and then use that to indirectly guide the patch conforming and delaunay mesh generation.

So the difference is less about the size functions and more about how the mesh uses the size function.

[Far]

But the gambit mesh stick (and more uniform) more to surface as compared to ICEM even though they are also using octree, denauly etc. e.g. mesh on high aspect ratio wing

TO me, the main difference is that the ICEM CFD tetra mesh is octree, and the mesh actually shows the sizing function directly. With Gambit, they actually run a size function controlled octree in the background and then use that to indirectly guide the patch conforming and delaunay mesh generation.

What is differnce between size function controlled octree and octree with size function?
I thought gambit needs the surfaces mesh first and that is patch conforming (as gambit is bottom up mesher).

When it uses dalaunay mesher?

[Far]

Ok. Here is full tutorial on hybrid 2d meshing in ICEM CFD. Everything is attached with post. Hope you will like it.

https://dl.dropboxusercontent.com/u/..._2dairfoil.rar

[sadjad.s]

TO me, the main difference is that the ICEM CFD tetra mesh is octree, and the mesh actually shows the sizing function directly. With Gambit, they actually run a size function controlled octree in the background and then use that to indirectly guide the patch conforming and delaunay mesh generation.

I think this post of Simon totally explains what Gambit does in Size function.
But the point is in 3D cases, with a little more job, by making nested densities we can get that size function. And it is actually just similar to what we get in gambit.

Ok. Here is full tutorial on hybrid 2d meshing in ICEM CFD. Everything is attached with post. Hope you will like it.

I would donate if I could due to these free and complete tutorials. Thank you.

[Far]

But the point is in 3D cases, with a little more job, by making nested densities we can get that size function. And it is actually just similar to what we get in gambit.

Thats the whole point. one of my friend is making surface mesh in gambit with very good and nice looking surface mesh in gambit with size function and also volume mesh with size function. The mesh density is very much fine where they want and mesh is much more uniform.

And then they take it to icem where they create geometry and insert 3d prism layers which is almost impossible in Gambit.

What I feel is that with ICEM Octree and patch independent surface mesh you can mesh a very complex geometry within few hours while in gmaibt you need detailed working in defining size functions for edges, surfaces and volumes. Sizing on each edge. Still Gambit has difficulty in making volume mesh. Moreover it does not support heavy meshes and hangs often.

Only requirement of ICEM is that you should know the appropriate settings for your model which I find some times difficult to get in first place.

[Far]

I would donate if I could due to these free and complete tutorials. Thank you.

I should have said that, this tutorial is based on instructions by Simon

[kozalp]

Originally Posted by Mmc

Hi Andrea,
How did you manage to create the region of the boundary layer by scaling the airfoil in icem? I have tried geometry/transform geometry/scale but the created curve is not satisfactory, it does not create a "parallel" airfoil with constant distance from the original airfoil.
Thanks,
Manuel

Hey Manuel,

Since your curve has a varying slope, you can't have a perfect boundary layer jus by scaling. If you look carefully the boundary layer which Andrea did, the distance between BL and geometry varies.
You can have a fine BL by scaling with different x and y offset coefficients.

If you want a perfect BL, you can do it following this steps:

1) You should know the equation of your curve or at least coordinates of points.
2) Then you can find slopes at given points by taking the first derivative of your curve equation or numerically deriving by using points.
3) Then calculate your max boundary layer thickness by using BL equation.
4) Find the points which will lay on your boundary curve by using the slope at each point and BL thickness.

I did it in excel. It takes time but, for me it was the only way to do it.

[jainanup27]

Originally Posted by Far

Ok. Here is full tutorial on hybrid 2d meshing in ICEM CFD. Everything is attached with post. Hope you will like it.

https://dl.dropboxusercontent.com/u/..._2dairfoil.rar

Hi Far,

I am not able to open the file. Can you please share it again?