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-   -   Rotating Region and mesh size (http://www.cfd-online.com/Forums/autodesk-simulation-cfd/118532-rotating-region-mesh-size.html)

QuentinMercier May 29, 2013 09:41

Rotating Region and mesh size
 
Hello Everyone,
First of all I want to apologize about my english, I am not a native.
I'm Quentin Mercier, a french student in mechanical engeneering.
Today I come to you because I have a problem with rotationnal region with Autodesk CDF simulation.
My purpose is to study a Savonius type wind turbine in dynamics, the huge problem I have is that I can't trust my results, because my mesh totaly influenced my results.
Here is a picture of my work:

http://imageshack.us/photo/my-images...sumaillage.jpg

yellow circle=rotating region
I can give you my boundaries:-pressure imposed at the the outlet
-wind celerity at the inlet (5000mm/s)
-normal celerity = 0 on the other sides of the air volume

I have tried many many many meshes for this problem and here are my results post treated (only rotationnal speed here in RPM during time)


http://imageshack.us/photo/my-images/843/imageforum.jpg

maille=1.00 is my reference mesh (automaticly calculated, approximatively 13,000 elements and maille=0.10 370,000). The 7 first plot has no rotationnal region included and the two last have.
Look at my results ... none of those can be trusted. Maybe you can help me about rotationnal region and with the mesh?



An other question I would ask you is about the inertia you should put in the rotationnal region.
Is this the inertia of the air volume contained in the region?
Or the inertia of my solid?


PS: my rotationnal region have a uniform mesh and I spread it to the entire volume (you can see it 1st picture)

Quentin

ApoloV May 29, 2013 14:12

This is also being discussed on the Product Forums for CFD


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