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October 16, 2013, 09:13 |
Flow in closed box ?
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#1 |
New Member
Borian
Join Date: Jan 2012
Location: USA
Posts: 9
Rep Power: 14 |
Dear All,
I have tried to run a OF simulation on a flow through/around a pipe which is in the middle of closed box .The case is 3D, incompressible, steady . See the attached picture for details. When my ''location-in-mesh'' point is inside the pipe , then sHM ignores the box and I get a solution/flow in the pipe only. When the ''location-in-mesh'' point is outside the pipe and inside the box respectively I have a flow/solution in the box ,but no flow in the pipe. See the attached picture - Box_No_Pipe, the pipe had not been meshed at all by SHM... I would appreciate any ideas! Is it so hard to simulate a flow in closed circuit? Thank you in advance! Kind regards, Boryan ================================================== ================== “Success is one percent inspiration, ninety-nine percent perspiration.” -Thomas Edison ================================================== ================== N.B. Damn right ... |
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October 16, 2013, 09:27 |
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#2 |
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Join Date: Nov 2012
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If I understand your problem correctly, maybe it would help to give a bit of thickness to the cylinder, i.e. to define the tube wall as the volume between two concentric cylinders.
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October 16, 2013, 10:12 |
Hi, thanks for the prompt reply
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#3 |
New Member
Borian
Join Date: Jan 2012
Location: USA
Posts: 9
Rep Power: 14 |
I fact the pipe wall is 10 mm thick. The whole pipe was removed from the mesh when ''location -in-mesh'' point was in the box, but outside the pipe...
Obviously snappy Hex Mesh renders my pressure INLET/OUTLET as a external boundaries of the flow domain and ignores any geometry outside it, i.e. the pipe... The general question is how one can possibly simulate such flow |
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October 16, 2013, 15:40 |
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#4 |
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Could you attach your case? It would be easier to understand the case this way.
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October 17, 2013, 05:59 |
Thanks for the interest!
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#5 |
New Member
Borian
Join Date: Jan 2012
Location: USA
Posts: 9
Rep Power: 14 |
The case is very simple, it is a part of bigger picture I would like to simulate. See the attached picture.
The pipe is in the middle of a closed box. Pressure INLET / OUTLET BC are applied on both ends of the pipe - 0 Pa & 500PA respectively. sHM ignores the pipe from the model when ''location-in-mesh'' point is outside the pipe and inside the box. Question is how one can simulate this in OF...Fluent runs closed circuit flows easily. Attaching of constant & system OF folders would not be useful as I use a bespoke version of OF. It seems to me that I need a ''multi-region'' solver... Regards, Boryan |
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October 17, 2013, 12:38 |
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#6 |
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Join Date: Nov 2012
Posts: 58
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I wanted to see exactly where "inlet" and "outlet" are in your system but you have verified my theory.
As far as I know, OpenFOAM does not allow internal patches, so, as you wrote, it recognizes them as external boundaries. Also, multi-region solvers do not work with two adjacent fluid zones... How exactly are you imposing the boundary values over there? |
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October 17, 2013, 12:46 |
How about a fan BC ?
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#7 |
New Member
Borian
Join Date: Jan 2012
Location: USA
Posts: 9
Rep Power: 14 |
Right now I am thinking about removing the pressure INLET / OUTLET BC's and introducing a fan BC in the middle of the pipe...the fan will drive the flow and hopefully this will solve the issue with the domain boundaries...
Strangely enough there are not many examples of flow in closed circuit .... |
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October 22, 2013, 11:48 |
Case solved !
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#8 |
New Member
Borian
Join Date: Jan 2012
Location: USA
Posts: 9
Rep Power: 14 |
After some heavy pondering over the case is solved now - one has to remove boundary patches as INLET/OUTLET from the stl. geometry and the case folders and introduce an internal face Fan (baffleZone true; ) on the place of the fan...big thanks to all guys who have helped me !
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