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[ICEM] 2d hemisphere in wind tunnel

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Old   June 3, 2012, 12:27
Default 2d hemisphere in wind tunnel
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i just wanna calculate drag of a hemisphere in wind tunnel .i had a problem in first step when i tried generate mesh file in icemi . i dont know which far field is better . i tried some but i had problem in aspect ratio . if some one can help me it would be great . i must add that wind hit the flat side of hemisphere in tunnel . sry for my bad english
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Old   June 3, 2012, 15:20
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Sijal Ahmed Memon (turboenginner@gmail.com)
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attach geometry file
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Old   June 4, 2012, 08:09
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i attached my icem file with a random farfield that i dont know if its good or not . tnx for your help
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File Type: zip hemisphere.zip (5.3 KB, 9 views)
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Old   June 4, 2012, 09:25
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Sijal Ahmed Memon (turboenginner@gmail.com)
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2d case..... Shouldn't it be 3d?
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Old   June 4, 2012, 10:18
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our teacher did it for a sphere with a bigger sphere for far field and as far as i know we do it in 2d and the axis line make it a perfect sphere . for my case i did same thing with hemisphere . for a sphere mesh had good quality but for hemishpere the flat line causes some aspect ratio problem .
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Old   June 4, 2012, 10:33
Default My favourite post
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Sijal Ahmed Memon (turboenginner@gmail.com)
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I like this post very much export hexa mesh to fluent
It is classical work using ICEM.
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Old   June 4, 2012, 11:23
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the topic you linked is great but i feel my issue is very simple and primary

the project our teacher wanna us to do is a simple one like the one he did in class (because we are beginner and amature )
here is a link for the one he did for sphere . he did it in 5 min and asked us do it for different geometry like mine(hemisphere)
and after that exported it to fluent . and i know what to do there for drag and ...
http://encodable.com/uploaddemo/files/sphere.zip
( i just wanna know how should i take my far field for a good blocking and after that meshing ) again sry for bad english

tnx a lot for your attention and time .
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Old   June 4, 2012, 12:12
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Sijal Ahmed Memon (turboenginner@gmail.com)
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Ok . Done in five minutes (I wasn't counting .)



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File Type: zip Sphere_windtunnel_sol1.zip (8.4 KB, 13 views)
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Old   June 4, 2012, 12:26
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Your case is much difficult than your teacher did.
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Old   June 4, 2012, 12:26
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here is how i changed the far field, of curse you need refinement so you can capture boundary layer. i suppose you know how to play with it. i'm sure there is a better blocking strategy
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File Type: jpg hemi.jpg (94.2 KB, 24 views)
Attached Files
File Type: zip hemisphere_ali.zip (10.7 KB, 8 views)
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Regards,
New to ICEM CFD, try this document --> http://goo.gl/G2gkE
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Old   June 4, 2012, 12:33
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tnx man you helped alot . now i must look at it and figure it out how u did that ( im amature as u know )
thank you very very much
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Old   June 4, 2012, 12:40
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Quote:
i must add that wind hit the flat side of hemisphere in tunnel
From left to right? Any angle of attack?
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Old   June 5, 2012, 07:00
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yes From left to right and no angle . btw you split it to 9 blocks ?
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Old   June 5, 2012, 07:56
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I just made three half ogirds. one for body, one for boundary layer and one for outer layer
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Old   June 5, 2012, 11:47
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I worked on what you suggested and here is what i did ( i should thank diamondx too ) . i think it has lots of problem . i exported it to fluent and when i checked quality the Minimum Orthogonal Quality was 6.62394e-01 . i dont know how i can enhance the quality .
http://uploading.com/files/c218e433/New%2Bfolder.zip/
and something else . i need check the drag coefficient from experiment with what i calculate . do you have any idea where i can find one? i search a little for it but i didnt find any .
again thanks for your help

* sry that i upload my file in different place . i just wanna some expert (like you )see it with detail and help me correct mine
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Old   June 5, 2012, 12:31
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0.6 is very good quality. Minimum needed is 0.01 by fluent. Meshing is good, but you have very fine mesh in far field..
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Old   June 5, 2012, 14:41
Question 3D hemisphere
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Hi, I have some problem related to this topic: I want to compute drag coefficient on a hemisphere and I know that the best way is an axisymmetric simulation. but for training I want to run a 3D simulation and need a 3D mesh.
actually I couldn't make a good one with ANSYS ICEM!
could you please help me?
Thanks.
Attached Files
File Type: zip Hemisphere 2.zip (3.4 KB, 5 views)
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Old   June 5, 2012, 15:09
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Follow shpere-cube tutorial. What do you mean by good quality?
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Old   June 5, 2012, 15:41
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were you looking for this. Just deleted lower part of sphere!!! do you need it? I am not sure.
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File Type: zip Hemisphere 3d.zip (18.2 KB, 11 views)
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Old   June 6, 2012, 10:09
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try this.......strategy is similar to sphere-cube tutorial
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File Type: zip hemisphere3d2.zip (15.6 KB, 10 views)
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