[GAMBIT] Negative Volume

aja1345 · August 26, 2015, 06:03

-mAx- · August 26, 2015, 06:44

did you delete previous mesh (with lower mesh option)?
check my mesh, very basic mesh, but good quality
Untitled.jpg

From this kind of mesh you can add a BL (you don't need to refine near the body since you will have a BL)

aja1345 · August 26, 2015, 07:25

Quote:

Originally Posted by -mAx-

did you delete previous mesh (with lower mesh option)?
check my mesh, very basic mesh, but good quality
Attachment 41652

From this kind of mesh you can add a BL (you don't need to refine near the body since you will have a BL)

Thanks,

But in this kind of mesh, the cells have excessive aspect ratio. And the transition between the BL and the mesh is to big (thin BL and coarse general mesh).

How to create the BL in this kind of mesh?

I am grateful that guide me more about creating the BL in this kind of mesh.

aja1345 · August 26, 2015, 08:01

Max, I understood your mean now!

Very thanks

If again I have the problem about negative volume, I post here.

thanks,

Best,

Aja

-mAx- · August 26, 2015, 08:16

with this mesh I don't see any aspect ratio problem.
Regardind the transition between core mesh and BL, you have to play with BL thickness

aja1345 · September 2, 2015, 07:59

Hi,

I have another question about mesh in Gambit.

Please see the following video(it is my work) and dbs file:

http://www.4shared.com/zip/PQAiPZ0Jce/Untitled_31.html

http://www.4shared.com/zip/AzdH69kib...pen_TE12-.html

When ratio is greater than 1.28, the negative volume is created. Why? I want to mesh finer.

Is there any adjustment that must be made in Gambit before starting the mesh?

Thanks a lot,

Best,

Aja

August 26, 2015, 06:44		#22
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	did you delete previous mesh (with lower mesh option)? check my mesh, very basic mesh, but good quality Untitled.jpg From this kind of mesh you can add a BL (you don't need to refine near the body since you will have a BL) aja1345 likes this. __________________ In memory of my friend Hervé: CFD engineer & freerider

August 26, 2015, 08:16		#25
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	with this mesh I don't see any aspect ratio problem. Regardind the transition between core mesh and BL, you have to play with BL thickness aja1345 likes this. __________________ In memory of my friend Hervé: CFD engineer & freerider

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August 26, 2015, 06:03		#21
aja1345 Senior Member Aja Join Date: Nov 2013 Posts: 496 Rep Power: 14

August 26, 2015, 08:01		#24
aja1345 Senior Member Aja Join Date: Nov 2013 Posts: 496 Rep Power: 14	Max, I understood your mean now! Very thanks If again I have the problem about negative volume, I post here. thanks, Best, Aja

September 2, 2015, 07:59		#26
aja1345 Senior Member Aja Join Date: Nov 2013 Posts: 496 Rep Power: 14	Hi, I have another question about mesh in Gambit. Please see the following video(it is my work) and dbs file: http://www.4shared.com/zip/PQAiPZ0Jce/Untitled_31.html http://www.4shared.com/zip/AzdH69kib...pen_TE12-.html When ratio is greater than 1.28, the negative volume is created. Why? I want to mesh finer. Is there any adjustment that must be made in Gambit before starting the mesh? Thanks a lot, Best, Aja