It is very sad that such a good tutorial gets not even 1k likes. It is because OpenFoam isn't even known by most of the engineers. I want to support you my friend.!! Good Work. Well Done!
Hi József, I will use OpenFOAM as a simulation tool for my Ph.D. project and I wanna thank you for your great material. I´m following your tutorials and I´m improving my skills to handle this software. Your videos have high quality, please keep posting. Many thanks!!!
When moving the trimesh next to the quad mesh around 5:10 you could also have used a split rendered view with linked cameras. That way you can zoom in on the same regions in both meshes at the same time.
Jozsef, great tutorial and I greatly appreciate you uploading this. I plan to go through your other videos after my success with this tutorial. Many thanks.
Thank you Josef for your time and effort doing these valuable screen casts. I wanted to comment saying that I could not find the transformation options under the properties panel in paraview. However, I managed doing this using filters. I might be missing some detail but that's how I managed doing it. I would also like to thank Tobias Holzmann for citing your videos as a reference.
Very good. You added information - I didn't get out of the intro tutorials (cavity and damBreak) - about the contents of the dictionary and source files that makes everything fit together much better.
Hello, thank u for your videos. It is a very good tutorial. I'm a Open FOAM begginner and I'm having a problem with the refined mesh, could you help me with this please? When i tried to refine the mesh with the "refineMesh -overwrite", a lot of similar FOAM warning appeared. For example: " --- > FOAM Warning: From function void Foam: : cellCuts: : setFromCellCutter(const Foam: :cellLooper&, const Foam: :List&) in file meshCut/cellCuts/cellCuts.C at line 2435 Found loop on cell 70291 that resulted in an unexcpected bad cut Suffestions: - Turn on the debug switch for 'cellCuts' to get geometry files that indentify this cell - Also keep in mind to check the defined reference directions, as these are most likely the origin of the problem " Because this is just a warning, i tried to run the simulation anyway, but there is a fatal erros: " --> FOAM FATAL IO ERROR; size 2200 is not equal to the given value of 8800 file: /home/andrenahes/andre-dir/elbowquad_refined/75/p From function Foam: : Field: :Field(const Foam: : word&, const Foam: : dictionary&, Foam: :label) [with Type = double; Foam: :label = int] in file /home/pawan/OpenFOAM/OpenFoam-v1912/src/OpenFOAM/lnInclude/Field.C at line 222 FOAM exiting" Also, before trying to refine the mesh all my simulations were working well and similar with your results. So, i'm guessing that the error is caused because the refine mesh. Thank you !!
I just started on my learning openfoam with a project of running backward facing step simulation using icofoam solver and was heavily confused with simulating the geometry ,like from which case file i can develop the geometry and give boundary conditions.And when i give the solver against cavity file in the cavity folder of icofoam tutorial that was copied to run folder ,it says error with polymesh and i tried giving ansToFoam cavity.ans ,but that didnt went well.And i m stuck as of now,that stuck brought me here and i m learning slowly i guess. Thank you so much jozsef, you are a real contributor and game changer for open foam beginners.
Hi, I do appreciate the help you are providing to learners like me. Thank You. I've question to you. Although, I managed to refine the quadmesh following your instructions, but the terminator gives me warnings. Can you give me any idea what's the possible reason behind these: 1.Refinement dictionary refineMeshDict not found 2.FOAM Warning : From function void Foam::cellCuts::setFromCellCutter(const Foam::cellLooper&, const Foam::List&) in file meshCut/cellCuts/cellCuts.C at line 2395 Found loop on cell 3319 that resulted in an unexpected bad cut. Suggestions: - Turn on the debug switch for 'cellCuts' to get geometry files that identify this cell. - Also keep in mind to check the defined reference directions, as these are most likely the origin of the problem. The warnings are given for a number of cells but I am showing you only one.
As long as they are warnings and no errors, it is ok for this tutorial. With refineMEshDict you can define the refinement, the second warning tells you about a bad cell refinement. As long as the simulation runs, you shouldn't worry about this.
@@OpenFOAMJozsefNagy Hello sir! Thanks for your great work with OF tutorials... I have the same issue and after this step, it will run up to a specific time point and exits with this error "Courant Number mean: 0.155452 max: 2.49183 " meaning the simulation wasnt converging due to those several warnings of bad cell cuts. After some seach on google, i figured out that " when the user doesn't use good enough directions for the cell cutting, there will be cells that are incorrectly cut and that could end up being a "needle in a haystack" that leads to a very bad mesh. Keep in mind that checkMesh might not complain about these unexpected incorrect cuts.". Meaning there is probably an issue with the configurations for the patchLocalCoeffs. in 10:00 it s the global coordinate system (tan1, tan2, normal). My question requires rather big answer, but in case it doesn't, are there any tips how to fix that without going way much deeper than "my league" if i could put it this way. Thanks!
I am using openFoam v7 (latest), paraview 5.6.something (latest), ubuntu 18.0.4. I guess, in case to save refineMesh from openFoam, you could do that from third parties like Meshlab, Blender, etc, right?
@@OpenFOAMJozsefNagy yea i just saw you did that thing in a next tutorial of urs and i returned to inform others who may have the same expirience... silly youtube didnt notify me for ur reply >< oh well, thanks a lot for the confirmation :)
Hi, Jozsef! When I used the command 'refineMesh -overwrite', it showed a warning as below. However, when I checked the mesh, there seemed to be fine. How to turn on the debug switch for 'cellCuts'? Do I still need to do anything to solve this warning? FOAM Warning : From function void Foam::cellCuts::setFromCellCutter(const Foam::cellLooper&, const Foam::List&) in file meshCut/cellCuts/cellCuts.C at line 2393 Found loop on cell 3200 that resulted in an unexpected bad cut. Suggestions: - Turn on the debug switch for 'cellCuts' to get geometry files that identify this cell. - Also keep in mind to check the defined reference directions, as these are most likely the origin of the problem.
Wonder if you think adding the linux history file in the "show more" section. The text on the command line can be a little difficult to read at times. All said and done thanks a ton for the tutorials.
This is a very good tutorial - very informative. Just one problem - Jozsef mentioned the word "homework" near the end - how frightening would that be! :=)
hello Josef, i have downloaded elbow quad mesh, when i import quad mesh, i am facing errors. can you please share the exact file in the description of your video?
Thanks for the awesome tutorials. 1 question.. where do I go if I want to design a cone type structure- an Abrams cone, which is 2 circles, one on top and the other bigger on at the bottom, such as to test a slump flow. Do I go into Icofoam?
Better tutorial than the official guide. But a small question:In your other videos, the annotations and lables are in the same direction of the color legend, but in this one, they are in the reverse side. How to reverse the annotations to the other side of the color legend in order to keep the annotations and lables in the same side? In my case, they are always in the opposed side, it is really annoying. Waiting for your reply. thanks
József Nagy For example, in the time of 16:00 in this video, there shows a color legend. We can find nnotations 0 and 4 in the downside and labels 1, 2, 3 in the upside of the color legend. How can we reverse the annotations 0 and 4 to the upside from the downside? Thanks
Shiqi Wang In this video I used the version 4.1 of Paraview. I the meanwhile I changed the version to 4.2. There the numbers are all on the same side. Just download the newest version and try it out. There under "edit color legend properties" you can change way more settings than in 4.1.
Hi, thank you for this nice tutorial. I have one question. In the tutorial folders of the openfoam 10 which I was using the refineMeshDict file was not present inside system/ . While executing the refineMesh -overwrite command, it was searching for the refineMeshDict file. After the command, the mesh was refined I reviewed in ParaView but the solution came out a blunder, nothing as other two solutions. What could be the case? I followed all steps according to your video.
Amazing tutorial. I just had a small issue with plot over line. I think I sort it out. If you try to do it, please make sure you plot on the case whose position is not translated. As there are 3 cases in Paraview opened and we translated the position at least two cases. If you generated the line on a contour which has translated, then you got nothing. Maybe you could try to add the translated coordiantes to resolve this as well.
Hi József, Would you happen to know if OpenFoam can store the residuals for each cell location? I have looked around but have not found any indication that this may be done presently. I need this in the context of mesh refinement - I have a coarse mesh that converges, while a very fine mesh does not, or at least does so much slower and the pressure residual shows oscillatory behaviour. I need to understand if this is do to the fact that the fine mesh is capturing some unsteady physics that the coarse mesh does not resolve (I'm running steady RANS) hence the convergence is hampered by this local unsteadiness. Any ideas? Thanks.
Hi Oscar. This is a good question and I am rather sure, that you are not the only one, who has this problem. Turbulence is mostly unsteady, you just assume a steady solution. I don't know of such a utility, try pisoFoam/pimpleFoam to check if your flow is unsteady. If it is, the steady solution is always questionable and on a coarser mesh, the solver might smear your results. This way it is possible to find a steady state solution. Still it will not be correct.
Thanks a lot for this wonderful tutorial. I encountered a problem while simulating for refined mesh. It shows floating point exception at time = 4.775 sec. Can you please tell me why it could have occurred and what should I change to overcome it?
What an awesome video. Thank you Jozsef, I can learn a lot from your videos. However, I cannot find the "translation" feature in my paraview. I am using paraview 5.4.1. Can you give me a solution to this problem? Thanks
I'm trying to simulate a fluid flow in a simple rectangular passage where i have a half circle appearing at the roof of the passage. The half circle has a radius as big as half the lenght of the passage. That said, i'm using icoFoam solver with a kinematic viscosity of 1. Then, the Courant number escalates very quickly, impossibilitating the simulation to end. Please, do you have any tip for that??
Hello. Excelent tuturial. However I have two questions. How does the refine command works? Because you decrease the timestep by a factor of 2 but in the command you didn't specify anything. There is any dict file for refine command? Can we use refine command with any kind of meshes?
+Carlos Completo refineMesh cuts all your cell through the "center", so instead of a cube you will have 8 cubes in 3D. With this your edge length is decreased by 2 and that is the reason for the factor of 2 in the time step. As far as I know this should work for all meshes.
While performing Filters -> Data Analysis -> Plot Over Line on the "elbow_quad_refined" case, although I provided the coordinates for start and end points of line, the plot is seemingly empty. What might be the cause for that ?
Thanks for the video! I have exactly the same version 4.1.0 of Paraview, but for some reason my parameter list on the left is much shorter! I don't have the "Transforming" section, only "Styling" and "Edge styling" -- so it's not possible to shift the elbow_tri results.
hi msr Najy, How are you? I'm PhD student , i'm beginneer in openFOAM and i need help pleaaase, i simulate the equation of Nernst-Planck (icoFoam solver) but I find a problem in the last term of the equation, how well I add this term (please see the equation below) dC/dt+div.(u*C)==div.(D*gradC)-div.(mu*E*C) mu and E is constant and E is the vector.
loved the tutorial..very informative, especially for beginner like me.. I followed all the things u mentioned but I'm not getting the 'Plot Over Line' correctly. The option is available under 'data analysis' as u said, but all values are 'NAN' and I couldn't figure out why.. I am using Paraview 5.8.0 Can you please suggest some soln as what might be going wrong?
A well made tutorial video. Thank you fpr you work. I got a question according the vim function. I couldn't change the numbers in my vim function. There were all highlighted in a different colour and were unable to change (had to use 10 instead of 75). Can you please tell me how i can change them? I am using OpenFOAM8 currently, if it is of help
FOAM Warning : From function void Foam::cellCuts::setFromCellCutter(const Foam::cellLooper&, const Foam::List&) in file meshCut/cellCuts/cellCuts.C at line 2393 Found loop on cell 3200 that resulted in an unexpected bad cut. Suggestions: - Turn on the debug switch for 'cellCuts' to get geometry files that identify this cell. - Also keep in mind to check the defined reference directions, as these are most likely the origin of the problem. got it when trying to refine the quadMesh, any suggestions ?
Hi jozsef, Thanks for this amazing tutorial. I am facing one trouble though. The problem is when i am trying to use the plot over the line option in paraview either one of two things happens: 1) "Plot over line" option is not even available on the list or 2) "Plot over line" is greyed out and not a possible option. I can't find any explanation for this as it seems that this filter option is the most basic and all tutorials say to use it .
I'm getting a problem when trying to calculate the square root for the cells in the end. When i type the exact same thing =sqrt(C2*C2+D2*D2) at the cell, a "#VALUE!" message appears. I can't figure it out.
What exactly did he mean by arc_length 22:23 . If the values are being recorded along a straight line(17:56), how did the even the concept of arc enter here?
hey. thank you for the tutorial. It has been a great help to me. when I run the command refineMesh -overwrite I get the following FOAM Warning : From function void Foam::cellCuts::setFromCellCutter(const Foam::cellLooper&, const Foam::List&) in file meshCut/cellCuts/cellCuts.C at line 2395 Found loop on cell 3200 that resulted in an unexpected bad cut. Suggestions: - Turn on the debug switch for 'cellCuts' to get geometry files that identify this cell. - Also keep in mind to check the defined reference directions, as these are most likely the origin of the problem. can anyone tell me why I am getting this response. I am new to openfoam and coding
Actually i have hp laptop with windows operating system in which i have installed ubantu 18.04.2 using oracle virtual box in which i am working with OpenFOAM version 18.1
When I tried the refineMesh command, I got the warning: "From function void Foam::cellCuts::setFromCellCutter(const Foam::cellLooper&, const Foam::List&) in file meshCut/cellCuts/cellCuts.C at line 2434 Found loop on cell 3200 that resulted in an unexpected bad cut." Subsequently, I opened paraview and saw that near the elbow, the mesh was warped - kind of going out of plane. I'm using Openfoam-v1906 on Ubuntu 18.04. Can you please suggest why this might happen?
Excellent tutorial while I have a small question. I followed your step, and my paraview version is same as yours(4.1.0 64-bit), however, I dont have "Plot Overline" in my Data Analysis list..What's going on?
Can you help please? While I was trying to plot over line, I got many errors and the plot over line tool just disappeared. I could not find any solution for this problem, and everything was going alright until that step. I urgently need a suggestion from you, sir. Thank you!
Update: It still is not seen in the data analysis section, however I can find plot over line by searching. But it keeps giving errors and is not plotting, hence I cannot get the graph.
Hi mate your tutorials are great! I followed the steps about the elbow quad_refined mesh, the simulation is working properly but I'm having a different Courant number from yours: Courant Number mean: 0.039958 max: 0.304754 How is that possible?
I found solution. I had to compile files again. If someone wants to know how to do it - here is answer: www.cfd-online.com/Forums/openfoam-meshing-utilities/171819-checkmesh-command-not-found.html Thank you for your interest in the problem. I close the topic.
what is he talking, a marsian language or what!? Are there easier ways than that code writing? do I need special training for CFD? I am interested to see some fluid flow simulation at work because I have 3D models of the pipelines and I am curious for turbulence, heat lost, pressure drop etc. But this looks very difficult, so I guess, I have to find a professional from freelance to do it.
When i try foamToVTK i get: --> FOAM FATAL IO ERROR: (openfoam-2206) size 2200 is not equal to the expected length 8800 file: 0/refinementLevel at line 19 to 2529. From Foam::Field::Field(const Foam::word&, const Foam::dictionary&, Foam::label) [with Type = double; Foam::label = int] in file /usr/src/packages/BUILD/src/OpenFOAM/lnInclude/Field.C at line 218. Does anyone has an idea what might be the reason for that?
