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January 15, 2018, 03:15 |
chtMultiRegionFoam case
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#1 |
Member
Join Date: Dec 2017
Location: Germany
Posts: 48
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Hey guys,
I am currently working on a case which I want to solve with the chtMultiRegionFoam solver and I have some questions on how to design my model so that it works without errors. To my case: I have a room with 2 cubes in it, 1 opening (inlet) on south side, 1 opening on north side and 1 Opening (outlet) in the ceiling. The cubes are heating the room up (heat source) and later I want to see how the air temperature changes when there is wind coming in (from the domain). Now I have some questions on how to make this work First of all the CAD or pre-processing: As far as I know I have to make multiple STL files. I would have made one for the room, 2 for the cubes. (or should I split the room into floor, walls, ceiling?) Do I also need to make a STL file of the air in the room and the inlets/outlets? Or will the wind (from the domain) flow right into the room if I just have opening in it? And some questions to the domain: I've set up the domain with blockMesh. Now the question is how do I add wind to the domain? And is there also a way to add a temperature to the domain which varies by time? Just like a daily temperature curve. If there is already another thread with same questions or a solution just let me know. I didn't find one :/ Any help and tip is appreciated Thanks in advance and keep on foaming guys |
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January 16, 2018, 03:56 |
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#2 |
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Anone an idea?
Are there good tutorials which I can look at? Need one with air as fluid and geometry meshed with SHM. |
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January 16, 2018, 04:55 |
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#4 | |
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Quote:
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January 16, 2018, 06:47 |
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#5 | |
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Ricky
Join Date: Jul 2014
Location: Germany
Posts: 78
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Have a look into the "incompressible/simpleFoam/motorBike" case, it is a wind tunnel simulation. The mesh is generated using snappyHexMesh with inlet, outlet, walls etc..
Quote:
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January 16, 2018, 12:19 |
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#6 |
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Your domain is fairly simple. Simply try it with blockMesh. One block for cube 1, another one for cube 2, and a few more for the room. Asign each block to a cellZone and split the resulting mesh into the resulting regions.
If you want to do it with snappyHexMesh you can create several stl files or since you only want to use cubes use the existing geometry sources like box. The tricky part is only how you choose to mesh the regions. You can use one snappyHexMeshDict and mesh all regions at once and again split the mesh afterwards or mesh each region separately. |
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January 17, 2018, 03:00 |
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#7 | |
Member
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Location: Germany
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The case I mentioned in the first post is a very simplified small one. I thought about doing it with blockMesh but want to work with SHM as I need it for my more complicated case later on. I do now have multiple stl files. 1 for the room, 1 for each cube and 1 for the air/fluid in the room.
I would've used splitMeshRegions command after succesfully meshing the geometry with SHM. I tried it out and it seems to work well. Just the geometry isn't where I want it in the domain. So currently I am setting up and checking all boundaries and trying to get the geometry at the right position. Quote:
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January 18, 2018, 11:28 |
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#8 | |
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Location: Germany
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So guys I changed my case a little bit and set up everything. It all works fine until I start the simulation.
It starts solving but then I get this error message: Quote:
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January 18, 2018, 13:25 |
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#9 | |
Member
Ricky
Join Date: Jul 2014
Location: Germany
Posts: 78
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did you declare "Umgebung" in constant/regionProperties under fluid?
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January 19, 2018, 02:39 |
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#10 | |
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Quote:
I will do now and see what happens. Last edited by Eko; January 19, 2018 at 08:27. Reason: solved |
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January 22, 2018, 06:31 |
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#11 |
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Location: Germany
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Simulation is running but I have a new issue. The cubes are heat sources so I made fvOptions files in constant/cube.
But when I start the simulation it doesn't seem to recognize these. So just to make sure - do the fvOptions file belong in constant or system/cube? Edit: Problem solved. fvOptions file in constant/region works. Last edited by Eko; January 24, 2018 at 06:04. |
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February 7, 2018, 07:16 |
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#12 |
Member
Join Date: Dec 2017
Location: Germany
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Hey guys I once more need your help
I want a wind in my domain with 5 m/s and have no clue how to deal with turbulence. I am using the k-epsilon model and wanted to ask if anyone knows how to get the right k and epsilon values? Or can I just assume that it is laminar and turn turbulence off? This is the last step. The simulation runs well with U=0 and laminar Last edited by Eko; February 8, 2018 at 06:56. |
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Tags |
chtmultiregionfoam, domain, heat source, snappyhexmesh, wind |
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