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connecting a small volume to the one containing it

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Old   November 2, 2008, 08:50
Default connecting a small volume to the one containing it
  #1
Djalil
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Hi, I want to follow an aerosol in a room (brick) containing a tubular reactor (small cylinder), which provides the energy for the movement. However, the particles produced at the entrance of the cylinder (velocity inlet)only move inside of it and dont get out through the outlet surface (pressure outlet) into the room. I suppose there is a problem of "connection" between the 2 volumes and I still dont get it fixed :-[ I hope someone can help!

kind regards!
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Old   November 3, 2008, 02:00
Default Re: connecting a small volume to the one containin
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mAx
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check in Gambit if your don't have 2 stacked surfaces, where you expect other results. If there are 2 surfaces (not connected), fluent understands that there's a wall
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Old   November 3, 2008, 04:17
Default Re: connecting a small volume to the one containin
  #3
Djalil
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Hi!

thx for your answer! Actually, when I use the "connectivity based coloring", the 2 faces of the cylinder are blue, like the brick, but not the body of the cylinder. I just created a brick, let's say 1x1x1 and a cylinder inside 0.3x0.1x0.1. Just trying to verify if everything is ok, I meshed all volumes and all faces (brick & cyl.) with 20 intervals. When I try to connect the 2 volume meshes, I get the error : cannot link 2 volumes because lower topology is inconsistently linked. Thus, I suppose I have first to connect the faces of the cylinder to the mesh of the brick volume... but I dont know how to do that ( thx for your help!
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Old   November 3, 2008, 05:03
Default Re: connecting a small volume to the one containin
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mAx
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You are trying to mesh 2 bodies which are overlapped. You have to split the brick with the cylinder. when you choose the brick, the outer surfaces from the cylinder should be also choosen (it shows that the split was successful) Then mesh the cylinder first, and finally the brick.

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Old   November 3, 2008, 06:35
Default Re: connecting a small volume to the one containin
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Djalil
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Hi mAx, thx for your quick answer! well, i still dont get it working. I think that s surely something easy, but it s boring! I describe u step by step what i do, so u may easily find what i m doing wrong : 1) I create the brick (1x1x1) 2) the cylinder (0.3x0.1x0.1) 3) I split the brick with the cylinder (coonected bientity) =>do i have to "retain" the cylinder? 4)i mesh the cylinder volume (lets say 10 intervals for a try) and then the brick (10 intervals) 5)i mesh all the faces (brick and cylinder, 10 intervals) =>do i have first to mesh the faces and then the volumes?does it make a difference if i mesh all faces at once, i.e. do i have to select/mesh each face separetely? 6)i set the boundary conditions : 6 faces of the brick=wall 1 face of the cylinder = velocity inlet 1 """""""""""""""""""" =pressure outlet 1 body of the cylinder = wall

I also tried to connect the faces of the cylinder to those of the modified brick, but it didnt bring me to more results!!!

restless to read you!

kind regards from france!

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Old   November 3, 2008, 07:24
Default Re: connecting a small volume to the one containin
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mAx
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I sent you an email
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Old   November 3, 2008, 08:18
Default Re: connecting a small volume to the one containin
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Djalil
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Thx,

i m waiting 2 get it!
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Old   November 3, 2008, 08:45
Default Re: connecting a small volume to the one containin
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Djalil
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Hi again, actually, i didnt get your mail! might you send it again?

kind regards
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Old   November 3, 2008, 08:58
Default Re: connecting a small volume to the one containin
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mAx
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si si je te l ai envoye envoie moi ta geometrie ou du moins ton fichier *.jou

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Old   November 3, 2008, 09:54
Default Re: connecting a small volume to the one containin
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djalil
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Salut, en fait je n'ai pas accès à ton mail, donc si tu peux me renvoyer un mail afin que j'ai ton adresse pour t envoyer mon maillage! Merci bcp encore
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Old   November 3, 2008, 10:24
Default Re: connecting a small volume to the one containin
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mAx
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c est fait
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Old   November 3, 2008, 15:38
Default Re: connecting a small volume to the one containin
  #12
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Hi France

At the step number 3, when you perform the split Gambit will produce two surfaces at the inrerface of every surface shared. I suggest that you delete one of the two surfaces and make only one surface that is shared by the two volumes. Hoping that may solve the easy bit.

Good luck
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Old   November 3, 2008, 15:49
Default Re: connecting a small volume to the one containin
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djalil
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thanks! I ll try to do that & explain here how i solved this problem. It s obviously not so complicated, but for beginners, it can be discouraging!
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Old   November 4, 2008, 14:23
Default Re: connecting a small volume to the one containin
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djalil
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So, it works (I mean that the mesh is consistent) : 1) draw the brick, then the cylinder 2) split the brick with the cylinder 3) mesh 4) CONNECT the fluid of the cylinder to that of the brick (that was what i forgot) 5) choose the inlet and outlet boudary conditions (in my case a "fan" and "interior" for the outlet, so that there are no special conditions for the outlet!

thx for your help, especially mAx!
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