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#1 |
Senior Member
teguh hady
Join Date: Aug 2009
Location: Saga, Japan
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Hi All,
In Modeling airfoil, I want to just make some variation of Angle of Attack. I hear that Grid Interface can make my job simpler. i read in tutorial of FLUENT there is correlation with TGRID. But i don't understand how it works. can you tell me How to make simulation by using grid interface?? ![]() teguhtf |
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#2 |
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Maxime Perelli
Join Date: Mar 2009
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You need to have 2 separated zones which are not connected.
At the interface between the 2 zones, you will have 2 superposed entities (edge for 2d, surface for 3d). Just define each entity as separated interface. Then in Fluent, define the couple of interfaces (define/interfaces) In your case, you create a circle around your airfoil, the interfaces will be the 2 superposed circles. Check Help (11. Modeling Flows Using Sliding and Deforming Meshes)
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#3 |
Senior Member
teguh hady
Join Date: Aug 2009
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Thanks For your response. I've tried. But i doesnt work. Here is my file. I jut want to rotate my foil.
http://rapidshare.com/files/29645441...RFACE.rar.html Thanks for your help!!! ![]() teguhtf |
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#4 |
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Maxime Perelli
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Will check it on Monday
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#5 |
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Maxime Perelli
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I check the dbs file and it is alright regarding the interface definitition.
So you shouldn't have proble to define them in fluent. What kinds of error do you get? 2 points on your gambit session. * your mesh should be refined around your moving body (in your case the mesh get coarser near the body) *you have to define the rotating domaine (surface) as separated fluid domain, because you will also rotate this region
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#6 |
Senior Member
teguh hady
Join Date: Aug 2009
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In my case, i don't use dynamic mesh in rotating things. I use Grid Interface to make my geometry become less than make geometry in each angle of attack. I hear that in ANSYS, I just make 2 geometry to complete my Angle of attack (I mean geometry of circle & rectangle and I just rotate my circle by using grid interface).
I'm sorry if my mesh is very poor. My focus on meshing is objected in quality of meshing. I don't know what is the best meshing!! Thanks for your help!! ![]() teguhtf |
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#7 |
Super Moderator
Maxime Perelli
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Ah ok, I thought you wanted your airfoil rotating. Sorry.
So you just have to rotate you middle surface in Gambit with your specific angle, and then export your mesh. I have no idea with Ansys. Regarding your mesh, and especially your grid interface, the mesh in this region has to be +/- with the same size. Best mesh is always quad/map, but the question is: can you afford spending many days trying to mesh your model with full hexa. In your case, don't hesitate you can easy mesh your stuff with hexa
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#8 |
Senior Member
teguh hady
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yes, I'll try it!
![]() In this problem, I use 2D solver. By the way, what is the meaning of "Regarding your mesh, and especially your grid interface, the mesh in this region has to be +/- with the same size"?? Is it meaning that the meshing of interface one and other must similar?? thank you very much!! teguhtf |
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#9 |
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Maxime Perelli
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not exactily similar, but not 5x bigger (resp. smaller).
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#10 |
Senior Member
teguh hady
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I'll try it.
Anyway, do you know the basic calculation of FLUENT in computing Lift Coefficient in 2D?? because There is no Area in 2D. Thank you!! teguhtf |
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#11 |
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Maxime Perelli
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I assume you have to enter a reference length in place of the area.
The coeff will be still dimensionless, as the force is computed on an edge (and not a surface)
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#12 |
Senior Member
teguh hady
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Thanks, by the way. when i use FLUENT 2D there is volume statistics when i check my *.msh. what is that?? I have thought before that the value of Cl based on that volume.
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#13 |
Super Moderator
Maxime Perelli
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check Mesh is only informations about your mesh topology/quality/etc...
No link with Cl
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