[erginbayrak]

Hello, I am a beginner user at ICEM CFD and I have a rectangular microchannel as you can see in the attachment. There is some corrugated protrusion at the local area of this channel. I couldn't form the boundary layers with O-grid (in ICEM CFD)to this corrugated surfaces. I'd appreciate if you could help me. Best regards,

[anand32]

Originally Posted by erginbayrak

Hello, I am a beginner user at ICEM CFD and I have a rectangular microchannel as you can see in the attachment. There is some corrugated protrusion at the local area of this channel. I couldn't form the boundary layers with O-grid (in ICEM CFD)to this corrugated surfaces. I'd appreciate if you could help me. Best regards,

Hi Ergin

Welcome to the Forum.

The rectangular microchannel shown in the picture will have the flow and consequently boundary layers INSIDE the channel, and not outside it.
So why do you need O Grid to capture the boundary layer?

You can very create a blocking using the extrusion method, and then to capture boundary layer effects, control the node distribution on the edge by using "Pre Mesh Paramaneters" option. There are many tools to control the node distribution- Bi-geometric, Geometric etc.

Let me know how it goes.

Anand

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[erginbayrak]

Thank you very much Dear Anand. I learned the extrusion method and formed the boundary layer by using O-grid as seen in an example attachment. But now, I couldn't form the block in core flow area. Is there any tool to form block by using corner vertices or any another method? Thanks again.

[anand32]

Originally Posted by erginbayrak

Thank you very much Dear Anand. I learned the extrusion method and formed the boundary layer by using O-grid as seen in an example attachment. But now, I couldn't form the block in core flow area. Is there any tool to form block by using corner vertices or any another method? Thanks again.

I am glad I was of help to you.

There is a tool to create blocks from vertices. It is just near the "extrusion" option.
Go to Blocking--> Create Blocks--> From Vertices/Faces.

Very Important: Be careful to select the vertices in the correct order. You may want to read the help manual for this.

Thank You

Anand

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If you want to learn ICEM from scratch, subscribe to my YouTube channel.

A First Course in ICEM Hexa

[erginbayrak]

Hi again,

I have been encountering some premesh problems as seen attached pictures. My mesh grids aren't suitable and very bad. Also, although, I have described the associations (can be seen yellow line), there is some missing surface near of corrugated surface. I need your helping. Thanks.

[anand32]

Originally Posted by erginbayrak

Hi again,

I have been encountering some premesh problems as seen attached pictures. My mesh grids aren't suitable and very bad. Also, although, I have described the associations (can be seen yellow line), there is some missing surface near of corrugated surface. I need your helping. Thanks.

It is difficult to judge without having the actual ICEM files but I will try.

If I were you, I would create a circle at every location inside the microchannel, wherever there is change in cross section- like from straight to corrugated and then corrugated to straight and so on.

So, when the O grid is created you can associate the O grid to these circles, this will help in creating more orthogonal meshes.

At last, you may also use move vertices- but only at last when everything else is taken care of.

Let me know if it turns out well.



PS: This video tutorial which meshes a pipe made up of 3 cylinders of different diameters, shows the meshing philosophy which I am trying to teach you.

3 Cylinders tutorial


Anand

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Learn ICEM from scratch my subscribing to my YouTube channel

A First Course In ICEM Hexa

[anand32]

Did you solve the problem?

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[erginbayrak]

Originally Posted by anand32

Did you solve the problem?

Sent from my Moto G (4) using CFD Online Forum mobile app

Hi Anand,

My friend has solved this problem by using only association and pre-mesh parameters (adjusting spacing and ratio for boundary layer) as seen attached jpegs. It doesn't need to use O-grid tool for boundary layer. Sometimes, we should think simple. But, I don't still understand why the extrusion method haven't worked. Thank you again Anand for your interest and helping. I have learned lots of things owing to your helping.

[anand32]

Hehe. I am happy for you.
I you look at my first reply, I had told you that O grid was not required for this.
Anyways. Nice that you got it fixed.

Sent from my Moto G (4) using CFD Online Forum mobile app