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Old   March 11, 2013, 12:39
Default Fluent Sliding Mesh Interface Problem
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tom h
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I'm currently attempting to simulate a VAWT using fluent but there seems to be a problem in my interface.

I'm using a flow velocity of 2m/s and have turned off the rotation to help identify the problem with the interface but it still seems to be interacting with the fluid when it should be passing through un-obstructed.

http://imgur.com/a/Fzcra

Any pointers or explanations regarding this would be much appreciated.

Tom H
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Old   March 17, 2013, 00:51
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Please, any help on the matter? I'm struggling to find a solution
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Old   March 18, 2013, 16:23
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Gowrav Shenoy
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Quote:
Originally Posted by badbeatz View Post
Please, any help on the matter? I'm struggling to find a solution
Hi,,
As per your mentioned data,, you are not defining rotation just to check how it will work when the rotor+blades at rest.. Correct me if my assumption is wrong.. And you are using Sliding mesh - Have you created two separate volume meshs for separate regions.. ie outside fluid and fluid around blades..?? If they are in single mesh,, defining interface may create problem..
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Old   March 19, 2013, 12:43
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Thanks for the reply!

I have tried defining both of them separately and this seems to yield the same result as when they are created under a single "Ctrl select" mesh.

The sliding mesh does rotate correctly when told to, but I changed it to 0rad/s in the images just to try and fix this issue.



It can also be seen from another persons simulation that they get errors near the boundaries of meshes using fluent. So I assumed it may be a common problem?

http://www.youtube.com/watch?v=7UwaX-SM7yc
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Old   March 24, 2013, 02:08
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I have managed to export the data to Ensight and it seems like my problem is the fluid within the mesh is rotating initially as well as the hydrofoils.

Is there any way to initially set the absolute velocity of the fluid within a Sliding Mesh to zero?
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Old   August 3, 2013, 06:39
Default Fluent Sliding Mesh Interface Problem
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Hi,

I am simulating also a VAWT for my PhD and have the same problem. I try different solutions and wasn´t able to solve it.

Any idea? Maybe we can discuss share knowledge with VAWT modelling.

Javier.
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Old   August 5, 2013, 09:00
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Paritosh Vasava
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You have not created any interface for your case.

In Ansys meshing: When you have interface you will have 'contacts' in the 'connections' part. If you do not have this, you can right-click on 'connections' and select 'Create Automatic Connections'.

In fluent: You will have atleast two boundaries whose name start with 'bonded-XXXX', an additional 'interior' boundary and a 'shadow' boundary. If you do not see this, you must go back to the meshing part and continue until you have an interface.
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Old   August 5, 2013, 17:24
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sari
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pardon me, i'd like to ask about tank simulation in a fluent. i've tried to follow step by step (exactly same with) the tutorial. modeling in rhinocerous, and then import the data in workbench. but there is some trouble when i try mesh it.
geom.png : my import .stp and i generate the import. just like in vid1.png

and then i try to edit mesh as tutorial, but there is (?) sign in geometry tree. as you can see in meshing.png whereas there's check list geometry at meshvid.png
beside, i take a look at workbench and the mesh part either have this sign (?) (mesh WB.png) while it is not happen in tutorial as in vid2.png

i really need help since i'm very beginer in fluent.
thank you,.
Attached Images
File Type: jpg geom.jpg (29.3 KB, 50 views)
File Type: jpg meshing.jpg (46.9 KB, 63 views)
File Type: jpg meshvid.jpg (29.0 KB, 57 views)
File Type: jpg mesh WB.jpg (24.6 KB, 46 views)
File Type: jpg vid2.jpg (42.2 KB, 43 views)
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Old   August 6, 2013, 02:15
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Paritosh Vasava
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For meshing (right side panel in meshing.jpg ) select 'Tetrahedral (Path Independent)' mesh method. It should work.
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Old   August 6, 2013, 14:18
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sari
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thank you. i've tried that one but still didn't work. is there any other way?
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Old   August 6, 2013, 15:59
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sari
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the physic in my layer is fluid while at tutorial is cfd (1.png). Is this difference impact to the result?
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File Type: jpg 1.jpg (45.0 KB, 30 views)
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