Boundary layer on Unstructured mesh

pendyala · August 7, 2013, 00:17

Hello All, I have a small question. Could we create a boundary layer on 3d unstrured mesh in gambit. I need to capture flow seperation and since, I cannot have a really fine mesh on my object, I wanted to use BL. This doesn't work. So any suggestions??
\

Thanks in advance.

-mAx- · August 7, 2013, 05:57

sure you can: http://aerojet.engr.ucdavis.edu/gamb...tm#mesh_blayer

pendyala · August 7, 2013, 09:53

The boundary layer is placed inside the body. Like on the surface, but can't it grow above the 3d structure? For ex in the sail boat meshing in gambit tutorial 14. I hope u got my question.

-mAx- · August 7, 2013, 10:34

in 3d the BL has to be attaches to the wall surface
Else post pictures

pendyala · August 7, 2013, 11:29

In the picture I uploaded to see the flow desperation I have to refine my mesh and since I cannot mesh so fine due to system limitations I have to have boundary layer. But when Put a boundary layer, I couldn't have it properly.

-mAx- · August 7, 2013, 11:38

display how look your BL like, even if you cannot create it.

pendyala · August 7, 2013, 11:59

I am currently out of my workspace. So cannot publish pictures right now. Will do shortly. In the image I updated its the front part of my body. If u observe there is higher space between each cell. So to decrease cell distance I want to lay a BL. How to attach a BL to this surface?? Do we go SELECT BL give the first length. If I do so, the BL grows on the surface of face . But it doesn't grown on top of face( grows exactly the way it is shown in link u posted). My basic is how to reduce the distance between cells without effecting

pendyala · August 7, 2013, 20:13

I want boundary layer in the edges in the 1 st block but I'm getting as in the picture..

pendyala · August 7, 2013, 20:23

Below image, as u see, in the 5 boxes box like faces available, I want to have BL on each face with spacing .00001 intial length. So, I couldn't ge that though. The while patch is the BL I'm getting. So, any suggesting as to how that works??

-mAx- · August 12, 2013, 00:41

in your picture I don't see any BL attached.
If you do it right, you select the surfaces of your body as attachment, and give first cell's height and also how many layers you want.

August 7, 2013, 00:17	Boundary layer on Unstructured mesh	#1
pendyala New Member ravi Join Date: Jul 2013 Posts: 12 Rep Power: 12	Hello All, I have a small question. Could we create a boundary layer on 3d unstrured mesh in gambit. I need to capture flow seperation and since, I cannot have a really fine mesh on my object, I wanted to use BL. This doesn't work. So any suggestions?? \ Thanks in advance.

August 7, 2013, 05:57		#2
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	sure you can: http://aerojet.engr.ucdavis.edu/gamb...tm#mesh_blayer __________________ In memory of my friend Hervé: CFD engineer & freerider

August 7, 2013, 10:34		#4
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	in 3d the BL has to be attaches to the wall surface Else post pictures __________________ In memory of my friend Hervé: CFD engineer & freerider

August 7, 2013, 11:29		#5
pendyala New Member ravi Join Date: Jul 2013 Posts: 12 Rep Power: 12	In the picture I uploaded to see the flow desperation I have to refine my mesh and since I cannot mesh so fine due to system limitations I have to have boundary layer. But when Put a boundary layer, I couldn't have it properly. Last edited by pendyala; August 7, 2013 at 20:15.

August 7, 2013, 11:38		#6
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	display how look your BL like, even if you cannot create it. __________________ In memory of my friend Hervé: CFD engineer & freerider

August 7, 2013, 09:53		#3
pendyala New Member ravi Join Date: Jul 2013 Posts: 12 Rep Power: 12	The boundary layer is placed inside the body. Like on the surface, but can't it grow above the 3d structure? For ex in the sail boat meshing in gambit tutorial 14. I hope u got my question.

August 7, 2013, 20:13		#8
pendyala New Member ravi Join Date: Jul 2013 Posts: 12 Rep Power: 12	I want boundary layer in the edges in the 1 st block but I'm getting as in the picture..

August 7, 2013, 20:23		#9
pendyala New Member ravi Join Date: Jul 2013 Posts: 12 Rep Power: 12	Below image, as u see, in the 5 boxes box like faces available, I want to have BL on each face with spacing .00001 intial length. So, I couldn't ge that though. The while patch is the BL I'm getting. So, any suggesting as to how that works??

August 12, 2013, 00:41		#10
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	in your picture I don't see any BL attached. If you do it right, you select the surfaces of your body as attachment, and give first cell's height and also how many layers you want. __________________ In memory of my friend Hervé: CFD engineer & freerider

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