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-   -   [ICEM] ICEM not resolving geometry (http://www.cfd-online.com/Forums/ansys-meshing/113208-icem-not-resolving-geometry.html)

CDollarsign February 14, 2013 16:59

ICEM not resolving geometry
 
Hello,

I am trying to model an S-Duct. I have made a good mesh, quality wise, but am getting oscillations in my pressure due to cells not being smooth. From what I can tell from visual inspection, the mesh fits the geometry very well, but from my pressure readings and first derivatives of the line from which I am reading pressure it is not so.

I have smoothed the mesh, but that messes with the quality. How could my un smoothed mesh appear to fit the geometry but not?

Here are pressure plots, and first derivative plots.

https://lh5.googleusercontent.com/-W.../s647/dydx.png

https://lh3.googleusercontent.com/-u...RY/s647/cp.png
How can I upload my grid for anyone to look at if they want?

CDollarsign February 14, 2013 19:11

I don't think my post was clear.

Here is a pressure contour of the inside of the wall of my duct.

https://lh5.googleusercontent.com/-f...ST-DB-2nd2.png

Since I am using RANS I only need to simulate half the model. Here is the interface of my symmetry plane and duct wall. It is perfectly straight and appears to hug the geometry of my duct well.

https://lh5.googleusercontent.com/-D...SST-DB-2nd.png

Far February 15, 2013 00:21

Would you like to show us domain and mesh?

OK I can see partial view of mesh and there is large jump in the cell size from symmetry to wall. Moreover it should be reversed.

CDollarsign February 15, 2013 12:25

Here is my computational domain:

https://lh4.googleusercontent.com/-V...462/Domain.PNG

Here is my mesh:

https://lh6.googleusercontent.com/-3...s1469/mesh.PNG

I know I have some spacing and cell stretch rate issues, but it seems my biggest is that the mesh is not projecting to the geometry correctly. I have the blocks associated to the lines and sufrace of the curved section but for some reason this is causing a piece-wise linear first derivative which is causing pressure waves in my calculation.

Far February 15, 2013 12:53

instead of mesh, you can upload .tin and .blk. zip them and upload on forum. I will check it ...

CDollarsign February 15, 2013 13:00

No .uns file?

CDollarsign February 15, 2013 13:07

2 Attachment(s)
here they are

CDollarsign February 15, 2013 16:03

I think that the mesh is not storing the curvature of the line, instead making it a faceted line, is there an option I am missing?


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