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[ICEM] setting B.C & FF shape for high A.O.A.

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Old   August 5, 2013, 00:40
Default setting B.C & FF shape for high A.O.A.
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Hi guys,
I recently have generated a hexa mesh of a fairing(see attached pics).

The mesh has ractangular far field(boundary surface of computational domain).

And set B.C to Velocity inlet, pressure outlet, symmetry (See attached pics.)

The blocking was OK, and simulation at 0 deg of A.O.A was also OK.
(see attached pics of B.C, residuals)

but I need to simulate with this configuration from 0 to 90 deg of A.O.As.

I have no idea that how to define B.C when A.O.A is very high.(e.g. 45 deg, 60 deg, 80, 90 deg..)

The freestream is 8m/s, so pressure-based solver is needed.

perhaps I can....
1. rotate geometry of faring, and blocking again.
2. change solver to density-based, and use pressure far-field B.C
3. change shape of FF surfaces.
4. Now is good, go on ....

How do you think? I need your help.

Best@Regards
Attached Images
File Type: jpg ICEMCFD.jpg (60.4 KB, 16 views)
File Type: jpg type3mesh2.jpg (93.3 KB, 20 views)
File Type: jpg type3_mesh5.jpg (92.8 KB, 19 views)
File Type: jpg residual.jpg (21.2 KB, 16 views)
File Type: jpg BC.jpg (57.7 KB, 17 views)
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Old   August 5, 2013, 01:55
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Don't touch the mesh, have you done the naca tutorial in fluent !? just change the velocity component x and y ie, when AOA is 0, x=1 and y=0 ...
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New to ICEM CFD, try this document --> http://goo.gl/G2gkE
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Old   August 5, 2013, 02:20
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Quote:
Originally Posted by diamondx View Post
Don't touch the mesh, have you done the naca tutorial in fluent !? just change the velocity component x and y ie, when AOA is 0, x=1 and y=0 ...
Thanks for your reply but...
I already know set angle of fresstream using vector. (e.g. at a.o.a. 15 deg,
x : cos15, y :sin15)

But when increasing a.o.a, reversed flow error occus at sudden a.o.a.

Now I'm trying that 0~45 deg : present B.C,
45~90 deg : change B.C of top surface to pressure outlet, and other to velocity inlet.
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Old   August 5, 2013, 07:44
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Couple of things.

1. Your mesh is very good. However at TE you should go for C type grid and collapse blocking. Do you have access to "Hexa blocking around cone" on ansys customer portal?

2. At 45 AOA you domain shape should be hemisphere at inlet and cylinder at outlet.

3. At 45 AOA the wake will be different. Therefore you need much denser in that region. So maybe Quarter O-grid is better option for your case. Or at least you should align mesh with flow.
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Old   August 6, 2013, 09:24
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1. I used y-blocks to capture sharp tail likes 'your' old post about "Rectangular Enclosure 3d wedge". (see attached pic)
And I wonder where ansys customer portal is.. I want to you to tell me.

2. sorry I can't understand.


Just in case, I uploaded prj files.

https://www.dropbox.com/s/r76m14aj8bwemn1/question.zip
Please, be more specific.

3. O.K. I wil, thanks.

Best&Regards

Quote:
Originally Posted by Far View Post
Couple of things.

1. Your mesh is very good. However at TE you should go for C type grid and collapse blocking. Do you have access to "Hexa blocking around cone" on ansys customer portal?

2. At 45 AOA you domain shape should be hemisphere at inlet and cylinder at outlet.

3. At 45 AOA the wake will be different. Therefore you need much denser in that region. So maybe Quarter O-grid is better option for your case. Or at least you should align mesh with flow.
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Old   August 7, 2013, 03:23
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Ok. Angle is not too sharp. You can go with current blocking at trailing edge.
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