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Continuity error cannot be removed by adjusting the outflow |
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September 21, 2018, 02:36 |
Continuity error cannot be removed by adjusting the outflow
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#1 |
Member
Mondal
Join Date: Sep 2018
Location: Canberra ACT
Posts: 68
Rep Power: 7 |
Hi Foamers,
I am a new OpenFOAM user. Now I am trying to simulate a case relating heat transfer in a cavity shape geometry just for learning. I choose buoyantsimplefoam for my case. I am trying to push the air (inside the cavity) from the patch called "Jet" created from top wall by using toposetdict and createpatchdict. All other walls are defined in the blockMeshdict file. For better understanding, I shared my case directory with this message. Please see the files and try to fix the problem. It will help me a lot. Thanks in advance. Anyways, The command lines are as follows, blockMesh topoSet createPatch -overwrite buoyantSimpleFoam paraFoam When I simulate my case I face the continuity error like that [code] Continuity error cannot be removed by adjusting the outflow. Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow. Total flux : 4.18896e-05 Specified mass inflow : 0.00269453 Specified mass outflow : 0 Adjustable mass outflow : 0 Last edited by Mondal131211; September 24, 2018 at 21:33. Reason: Update |
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September 24, 2018, 04:34 |
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#2 | |
Super Moderator
Tobias Holzmann
Join Date: Oct 2010
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Hi,
please use code tags around your terminal outputs to improve the readability of your stuff. Additionally, I think that your statement Quote:
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Keep foaming, Tobias Holzmann |
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September 24, 2018, 21:08 |
Continuity error cannot be removed by adjusting the outflow.
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#3 | |
Member
Mondal
Join Date: Sep 2018
Location: Canberra ACT
Posts: 68
Rep Power: 7 |
Quote:
Thank you for your response. Actually, I am new in this forum. This is my first post. That is why I could not make my post attractive to the forum stuff. Anyways, I am now trying to simulate a case like a cavity shape by buoyantsimplefoam. I want to push the air inside the cavity by a patch called "Jet" (created from top wall by using toposetdict and createpatchdict) in my simulations while the left wall is considered hot and right wall is cold wall. For the clear understanding about my simulation, I attached my case directory with the problem image in this message. Please see the attached file here and try to solve my problem. it will help me a lot. How to set reference pressure in BC? I am quite new with OpenFOAM. Sorry for bothering. |
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September 26, 2018, 05:21 |
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#4 |
Super Moderator
Tobias Holzmann
Join Date: Oct 2010
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Dear Mondal,
I will have a look at your case today in the evening - if there is time. However, I will not solve your problem and give you the answer straightaways. I might give you hints but the best way to learn FOAM is to solve the problems yourself. Keep in mind, that the basics of numerics are a fundamental part of applying appropriate boundary conditions. To you question - set reference pressure: - you cannot set a reference pressure in the boundaries (that does not make sense) - you can set a reference pressure at a specific numerical cell within the fvSolutions file; however, this is only needed for closed domains (no inlet/outlet).
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Keep foaming, Tobias Holzmann |
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September 26, 2018, 07:18 |
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#5 |
Member
Mondal
Join Date: Sep 2018
Location: Canberra ACT
Posts: 68
Rep Power: 7 |
Hi Tobi,
I have been trying this problem for almost one month. But it shows same problem each time. However, please have a look my case directories and give me hints if there any other problem. Thank you very much for your help. |
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September 26, 2018, 21:14 |
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#7 | |
Member
Mondal
Join Date: Sep 2018
Location: Canberra ACT
Posts: 68
Rep Power: 7 |
Quote:
I am very happy to see this kind of picture. Thank you very much. I checked the boundary conditions and this time iteration is running but is not converging on my solution. After 118 iterations simulations stopped and show the error like this. Below error message, I also add my defined p_rgh file that runs 118 iterations and stooped. I think I am really disturbing you. I am just starting to learn OpenFOAM that's why I ask very silly things about my simulations. I have to solve this problem in any way as early as possible. Any suggestions for that error? Code:
...........bounding k, min: -42.1468 max: 482.077 average: 0.350154 #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/lib/x86_64-linux-gnu/libc.so.6" #3 log in "/lib/x86_64-linux-gnu/libm.so.6" #4 Foam::nutUWallFunctionFvPatchScalarField::calcYPlus(Foam::Field<double> const&) const at ??:? #5 Foam::nutUWallFunctionFvPatchScalarField::calcNut() const at ??:? #6 Foam::nutWallFunctionFvPatchScalarField::updateCoeffs() at ??:? #7 Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::GeometricBoundaryField::evaluate() at ??:? #8 Foam::RASModels::kEpsilon<Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Foam::CompressibleTurbulenceModel<Foam::fluidThermo> > > >::correctNut() at ??:? #9 Foam::RASModels::kEpsilon<Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Foam::CompressibleTurbulenceModel<Foam::fluidThermo> > > >::correct() at ??:? #10 ? at ??:? #11 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #12 ? at ??:? Floating point exception (core dumped) ............... FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object p_rgh; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // p_rgh........... dimensions [1 -1 -2 0 0 0 0]; internalField uniform 1e5; boundaryField { cold { //type fixedFluxPressure; type fixedValue; value uniform 1e5; } hot { //type fixedFluxPressure; type fixedValue; value uniform 1e5; } top { //type fixedFluxPressure; type fixedValue; value uniform 1e5; } bottom { //type fixedFluxPressure; type fixedValue; value uniform 1e5; } front { //type fixedFluxPressure; type fixedValue; value uniform 1e5; } back { //type fixedFluxPressure; type fixedValue; value uniform 1e5; } Jet { //type zeroGradient; type fixedValue; value uniform 1e5; } } Last edited by Tobi; September 27, 2018 at 01:53. |
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September 27, 2018, 01:49 |
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#8 |
Super Moderator
Tobias Holzmann
Join Date: Oct 2010
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I am not investigating into that problem because:
For your interest, the quantity k makes trouble. Code:
bounding k, min: -42.1468 max: 482.077 average: 0.350154 Good luck. PS: Please use C O D E T A G S
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Keep foaming, Tobias Holzmann |
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