Note, the setting div(phi,U) Gauss linearUpwind grad(U); in fvSchemes. Gauss linear (pure 2nd Order scheme) leads to nonphysically oscillation of the velocity field if the mesh is moving even for a structured mesh.
Hi Jozsef, Thank you so very much for your tutorials!!! Can I please know what are changes we need to make if we want to run a steady simulation? i.e. using simpleFoam solver Thank you so much!
@@OpenFOAMJozsefNagy Sir, i had the same question.. Is it impossible to run a steady state simulation for fan/pump kind of problems in openfoam? Like mrf approach?
Great and very helpful tutorial! @József Nagy is the AMI a hollow or a plain cylinder? I downloaded the geometry and tried to have a look on the AMI stl file as a part file in Creo Parametrics, i had problems but the AMI seems solid?
Hi! This video is awesome thanks. If I have a case where the rotation of the mesh is determined by the surface forces acting in my geometry (i.e a fluid-structure case). Does OpenFOAM has a case/code where you can simulate that?
Hello ! Im new in openfoam so the question may be a bit silly... when doing the surfaceFeatureExtract, I get an error that says: keyword extractfromsurfaceCoeff is undefined in dictionary. How can I solve it ? Thank you in advance!
Hello József, thanks for all the work in putting this together ! I noticed when running this that my fan isn't actually rotating as I move forward in time. Does this suggest that I need to make changes to the boundary condition specifications? I am using v10 so I had to make some minor syntax changes specifically in the createPatch, DecomposePar and surfaceFeatures dict. Furthermore, I gather that the AMI condition for simulating rotation is being phased out, is this correct and should this case still run in v10?
Unfortunately the .org version is by design not compatible with any other versions, so you are on your own. I would suggest to switch to the .com version, which values backwards compatibility.
Hi jozsef! I modified the geometry of this tutorial in blender (basically mirrored the fan and AMI). The snappyHexMesh was successful with one rotatingzone cellzone formed. Now I want to define two rotating mesh regions but my simulation crashes without any error after defining two rotating mesh regions using dynamicMultiMotionSolverFvMesh. I think the error lies in dynamic mesh. Is it because there is only one cellzone? Any guidance would be appreciated. Thanks alot for these tutorials!
You need multiBodyMotion, check which version of OpenFOAM you have and go through the tutorials folder for a tutorial which uses multiple AMI-s and us e the syntax there.
Thank you! It's very clear. I have a question, though. Where did you set the AMI_slave patch? It seems like the geometry only has 1 surface for AMI patch called "AMI"
Is there a possibility of having laminar flow in rotating problems? What is the characteristic velocity in these cases, the rotational velocity (omega*R) ?
Hello József, I have few questions regarding cyclicAMI patch.. 1) How does openfoam differentiate AMI1 & AMI2...?? Do I need to give that patch name in geometry file...??? 2) In this case, you have used the hollow cylinder geometry as AMI.stl , the rotating zone should always be hollow or shell type...?? & does it must be closed body...???
Thanks a lot, József! I just found your tutorials, which is a huge help starting with OpenFOAM. Although having 0 experience with CFD, I find it very interesting (and even perhaps useful in my work). With that said, would it be possible for you to speak more about some of the parameters, which OpenFOAM users might want to change running their simulation cases? For example, what do certain constant/parameters mean (physical meaning), what could we expect, if we change them (it is very clear, what would happen with changing gravity sign, but less clear with other constants/parameters); e.g. what does nu in Newtonian stand for? Shall the value be changed? (just as example). Perhaps it would be possible, to add comments in the tutorial files, which holds all those constants and parameters, what is where, and what each of them do/and does it need to be changed in certain cases (if some OpenFOAM user has this done, could you please share such files, I believe it would be great help for those who just start)? Myself, I am interested in aerosol particle flow simulation. I would highly appreciate, if someone could share particle simulation related OpenFOAM tutorial files, which include explanations for constants and other parameters (e.g. physical meaning; which parameters/constants should be changed). This is perhaps a lot to ask, because everything depends on the case... But I thought to try anyways. I thank you once again for such a beautiful material!
Hello József, thank you for putting this video together. It was really helpful. Could you please point to which line in the dictionary file is actually creating two surface meshes, AMI and AMI_slave, from one geometry which is AMI.stl? Thank you.
Thank you for the very insightful tutorial! I learned much about dynamic meshing and parameters to consider in simulating rotation. However, in running this tutorial, I encountered a problem with relVelocity wherein a FOAM FATAL IO ERROR is met when trying to wmake the function.
@@OpenFOAMJozsefNagy It is a function included in the system folder of the most recent iteration of the tutorial case files. It wasn't discussed in the video nor was it mentioned in the openfoam .com tutorial.
@@OpenFOAMJozsefNagy Regardless, I just removed the function and the simulation seems to be running well. Just a heads up for those encountering the same problem.
While running surfaceFeatureExtract I get this error "keyword extractFromSurfaceCoeffs is undefined". I added that keyword and it ran successfully but I get this line saying "Feature line extraction is valid on closed manifold surfaces only".
@@parasghumare5864 Hello, I use openFoam7 and I had the same problem as you. You can try this: in the ControlDict file, replace writeControl adjustable; by writeControl adjustableRunTime; and in the file surfaceFeatureExtractDict, replace door.stl { extractionMethod extractFromSurface; includedAngle 150; } by this: door.stl { extractionMethod extractFromSurface; extractFromSurfaceCoeffs { includedAngle 150; } writeObj yes; } do the same for each.stl file I haven't finished the tutorial yet, but by making these changes, I managed to generate the mesh and view it in paraview
@@eti1316 i have already finished the tutorial and some of the changes I had made are the ones you have suggested. I was just wondering what that warning line means?
Respected Professor, Really useful tutorial. I had a doubt, If I am exporting the mesh from Ansys, how I can specify the movingWallVelocity/cyclicAMI type? Thank you
Is ceiling part inside AMI zone treated as rotating object too, or its data are interpolated to behave static? I mean if i leave some wall mesh elements inside this zone does it act like movingWallVelocity against my flow?
Firstly, thank you for your work. I have a question: Can I define two rotating mesh regions with different rotational speeds? If yes how would I define them in dynamicMeshDict. Could I simply write rotatingZone1 {solidBodyRotationFunction ....; origin ....; axis ...; omega ...;} and rotatingZone2 {........}?
Hello! I want to do the same but my simulation crashes without any error after defining two rotating mesh regions using dynamicMultiMotionSolverFvMesh. I think the error lies in dynamic mesh. Were you able to successfully simulate two dynamic mesh regions?
Thank you for this tutorial! I have some questions about this case: Using ./Allrun with OpenFOAM 5.x does not provide a solution. Is this because of the version of OpenFOAM? When entering commands individually instead of using the batch files, the case meshes and converges, but the fan does not spin. What could be preventing the fan from spinning? Thanks!
Hi József, why is it necessary to use the "movingWallVelocity" for the U field? Why is it not useful to apply the noSlip condition there or a fixed value of (0 0 0)? Since the fan and the cells within the AMI patch are rotating, I thought that a noSlip wall is enough. It seems that this is not the case. With respect to the turbulent fields you used the same wall functions for the fan wall as for the other walls and no special moving wall function. The explantion of "movingWallVelocity" in the documentation: "Sets the velocity to the desired value for moving walls when employed in moving mesh cases" is not very meaningful to me. I would appreciate some further explanation. Very interesting video. Thanks!
movingWallVelocity leads to a velocity of 2 * pi * Rotational speed * Radius at the cells of the patch. It is determined by (pp.faceCentres() - oldFc)/deltaT. Location of new patch cell center - old patch cell center divided by the time step size.
@@OpenFOAMJozsefNagy If I put empty in the boundaries conditions of certain "walls", OF considers that the simulation its done in 2D? That "wall" should have any special name? or I could rename as front and back for example?
@@OpenFOAMJozsefNagy I've manage to adapt your case to my situation. After a while (0,26 seconds) the simulation crashs and gives the error exit 142. Do you know what it means? Thanks
@@OpenFOAMJozsefNagy Don't have OF setup at the moment.... Do we still need to have openings in the room floor for the surfaces of the table's feet ? (The surface of the table foot in contact with the surface of the room floor; this would create non-manifold instances, yes ?)
I could just download the files and look, couldn't I ?. [EDIT: Yeah, the table is a solid item and there are no opening in the room floor for the feet. Only opening in the room for the door and window. This would hugely simplify my Rhino work as previously I have been merging all items into a single, solid STL.]
I've been trying to adapt this template to run a quadcopter simulation (4 rotating AMI zones) with dynamicMultiMotionSolverFvMesh. I keep getting floating point errors :S
Hi Jozsef, i wanted to give the tutorial a try but i can't seems to download the case files with the link provided. I got page not found error when i click on the link to the files.
Great work. I am thinking of using OF for high speed turbomachinery applications like gas turbine turbofans . Do we have any such tutorial I can refer to thank you
After a longer break from simulation I started this tutorial again, what could be the reason that when I create folders in windows there are shown in ubuntu but I can't open them? Do you have any advise?Thank you.
@@OpenFOAMJozsefNagy Thank you for your reply.I checked your geometry, the AMI is just a shell, is that the right way? Can the AMI just be a solid cylinder? Also, it seems that the inlet, outlet, and the room are just faces or thin layers.
@@OpenFOAMJozsefNagy But if that's the case then why did you put the value as uniform 0? Why didn't you assign a rotatingWallVelocity BC and specify the rotation characteristics? Bit confused 😅
@@parasghumare5502 uniform 0 ist a starting value and is overwritten by the code. The rotation characteristics are not specified in the BC but in the dictionary in constant.
Is it possible to simulate half domain (a symmetric one) with a sliding mesh in openfoam? Then use symmetry conditions.... would that work? I actually tried it some time ago and it crashed Cheers!
@@OpenFOAMJozsefNagy Thank you so much for your reply! Sorry for getting back so late. May i also check if this method applies only for transient or does it apply for steady state simulation as well? Thanks again!!
Hi Joszef, I'm fairly new to openfoam and I am getting this error when running the mpirun command: environment variable MPI_BUFFER_SIZE not defined. How can I solve this issue? Thanks in advance
Great tutorial, very useful! I noticed you indicated an angular velocity as the driving factor, but is it possible to specify the air as the driving factor? If so, how? To give an example of what I mean, right now you have a motor turning the ceiling fan at a constant velocity, but I'm interested in simulating a wind turbine spinning up from 0 omega based on the windspeed acting on the blades. Best regards!
Thank you very much sir! I have a big problem about what kinds of boundary type should we choose, for example in this tutorial. This confused me and my friends.
Hello, I'm trying to run the surfaceFeatureExtract command, but I get a message that says this: surfaceFeatureExtract: symbol lookup error: surfaceFeatureExtract: undefined symbol: _ZN4Foam9UOPstream5writeERKNS_5tokenE and I cannot pass from here :( I've tried downloading the whole source code and running it from there, bu I have the same message, I wonder if you could help me please.
I had the same problem at first. It went away after a complete delete and reinstallation of OpenFOAM. But in the second run i got the error that controlDict, using the surfaceFeatureExtract function, cannot be found. Looks like this: FOAM FATAL ERROR : Could not find mandatory etc entry (mode=ugo) 'controlDict'
hello thank you for your tutorials i have make all the instruction in this video but in the end when i run the simulation the fan doesn't rotate ; i didn't understand what i should change. thank you
@@OpenFOAMJozsefNagyexactly like you have done for the door and the outlet but generally i have all done like you but the problem is that the fan doesn't rotate in the simulation thank you for your help
@@OpenFOAMJozsefNagy Dear Sir, I have problem with local porosity distribution along length and width, the available solver only handle the constant porosity. Can You please help me to sort it out? Thanks in Advance.
Hi Jozsef, i tired to make this tutorial which is really good to learn something. I had a problem when i run the simulation, this is look like due to relVelocity/ Using dynamicCode for functionObject relVelocity at line 13 in "/home/aokaya/OpenFOAM_files/rotatingFanInRoom/case/system/controlDict.functions.relVelocity". Thanks For videos and helps.
Hello Józef, I have a one question. I can't start my simulation. I have this ERROR during last step in tutorial. [0] --> FOAM FATAL IO ERROR: [0] Wrong token type - expected string, found on line 20: word 'fvMotionSolvers' [0] [0] file: /mnt/c/Users/monki/Documents/rotatingFanInRoom/case/constant/dynamicMeshDict.motionSolverLibs at line 20. [0] [0] From function Foam::Istream& Foam::operator>>(Foam::Istream&, Foam::fileName&) [0] in file primitives/strings/fileName/fileNameIO.C at line 60. [1] --> FOAM FATAL IO ERROR: [1] Wrong token type - expected string, found on line 0: word 'fvMotionSolvers' [1] [1] file: IOstream.motionSolverLibs at line 0. [1] [1] From function Foam::Istream& Foam::operator>>(Foam::Istream&, Foam::fileName&) [1] in file primitives/strings/fileName/fileNameIO.C at line 60.[2] I have OPv1906 installed from your tutorial on Ubuntu in Windows 10. How can I solve it ? Thank you in advance! Best regards!
For people who as me had the same error, it should be solve with "fvMotionSolvers" in the motionSolverLibs of the dynamicMeshDict of system folder, this is just to indicate that is a string.
For the tutorial files working with openfoam v8 search in git hub for josoHub/rotatingFanInRoomOFv8. Please read the file README for instructions. And thanks for the tutorial.
Hi Jozsef, I have tried to modify this tutorial by replacing the geometry. But I cannot run the simulation, could you please check my geometry? I will send it to your email if you have time to take a look at them.
Check to Allrun script, OpenCFD moved the STL files to a different location. If you check the tutorial folder of your v2012 installtion the files are still there.
Great tutorial. Sir I have a question here. How big we should define this rotating domain size. For propeller or fan, yes I agree the rotating domain shape is cylinder. But I'm not clear about the distance from the propeller or fan to the faces of the cylinder (read : cylinder radius and length). It would be nice if somebody could enlighten me. Sorry for the trouble and have a nice day to you all ;)
It should be as close to the fan as possibly, but the refinement of the fan/blade should not influence the refinement on the AMI. At least this is my experience.
@@OpenFOAMJozsefNagy thanks alot for the reply Sir. Your experience is valuable to me since this is what I lack of as relatively new explorer in dynamic mesh user. So, based on your experience, this is what I get : suppose my AMI refinement level is less than the refinement in propeller surface. While I define AMI surface to get as close as possible to the propeller, I should be careful to define the distance from the AMI to the propeller so that pre-set AMI surface refinement level not affected by colateral or induced refinement from more refined propeller surface? Could you elaborate why this consideration is important. Just for the info, right now I'm predicting thrust of 2 meters of diameter of fixed pitch propeller for the aircraft rotating at 2200 rpm by using CFD. I consider using compressible solver and I have tried CFD simulation in openfoam using MRF approach (steady) and sliding/rotating mesh or AMI (transient).
Thank you for noticing. They changed the address to it. I updated it in the description. develop.openfoam.com/Development/openfoam/tree/develop/tutorials/incompressible/pimpleFoam/RAS/rotatingFanInRoom
Hi Jozsef, dear community thanks for your tutorial it was very helpful. With your video and the entry on the OpenFoam website i was able to finish the tutorial. I tried to change the geometry and it worked until the last command. When i try to run mpirun -np 4 pimpleFoam -parallel > log.pimpleFoam & the following problem report appears. [0] --> FOAM FATAL IO ERROR: (openfoam-2112) [0] Cannot find patchField entry for procBoundary0to1 [0] [0] file: processor0/0/p.boundaryField at line 25 to 62. [0] [0] From void Foam::GeometricField::Boundary::readField(const Foam::DimensionedField&, const Foam::dictionary&) [with Type = double; PatchField = Foam::fvPatchField; GeoMesh = Foam::volMesh] [0] in file /usr/src/packages/BUILD/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 172. [0] FOAM parallel run exiting [0] in file /usr/src/packages/BUILD/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 172. Any help would be appreciated. With kind regards Benedikt Bihlmayer
@@OpenFOAMJozsefNagy Hi Jozsef, I tried to run the simulation again and edited the code. You were right that during decomposePar was the following issue --> FOAM FATAL IO ERROR: (openfoam-2112) Cannot find patchField entry for allBoundary file: 0/k.boundaryField at line 25 to 62. From void Foam::GeometricField::Boundary::readField(const Foam::DimensionedField&, const Foam::dictionary&) [with Type = double; PatchField = Foam::fvPatchField; GeoMesh = Foam::volMesh] in file /usr/src/packages/BUILD/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 172. It would be great if you can tell me what i am doing wrong. Thanks for your help i do appreciate it a lot. With kind regards Benedikt Bihlmayer
@@benediktbihlmayer9004 Your original BC from blockMesh is not deleted during snappy. Take a look at your mesh. Looks like you don't cut away your outside for some reason. Not water tight STLs?
@@OpenFOAMJozsefNagy How can i check, if the STLs are water tight? I thought by running the command checkMesh i see if there is a problem but checkMesh returns that everything is ok. Checking topology... Boundary definition OK. Cell to face addressing OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces... Patch Faces Points Surface topology allBoundary 14350 14352 ok (closed singly connected) Checking faceZone topology for multiply connected surfaces... No faceZones found. Checking basic cellZone addressing... No cellZones found. Checking geometry... Overall domain bounding box (-277 -47 -97) (1 47 47) Mesh has 3 geometric (non-empty/wedge) directions (1 1 1) Mesh has 3 solution (non-empty) directions (1 1 1) Boundary openness (-1.330152e-17 1.824875e-15 -1.336859e-15) OK. Max cell openness = 1.734963e-16 OK. Max aspect ratio = 2.808359 OK. Minimum face area = 7.285986. Maximum face area = 20.52812. Face area magnitudes OK. Min volume = 34.97463. Max volume = 35.08443. Total volume = 3756917. Cell volumes OK. Mesh non-orthogonality Max: 0.3553395 average: 0.1683 Non-orthogonality check OK. Face pyramids OK. Max skewness = 0.006983165 OK. Coupled point location match (average 0) OK. Mesh OK. Do you know any other options to take a closer look at the mesh? With kind regards Benedikt Bihlmayer
HiJozsef, when I run surfaceFeatureExtract, it says symbol error. And I can only find surfaceFeature and surfaceFeatureConvert in the utilities directory. Is it because of the difference due to the latest version of openfoam?
![[OpenFoam Tutorial 5] Turbulent Flow in a Pipe with Salome as Mesher](http://i.ytimg.com/vi/IJLROB28nXE/mqdefault.jpg)
Note, the setting div(phi,U) Gauss linearUpwind grad(U); in fvSchemes. Gauss linear (pure 2nd Order scheme) leads to nonphysically oscillation of the velocity field if the mesh is moving even for a structured mesh.
I appreciate your work. Thanks
Thank you!
Hi Jozsef,
Thank you so very much for your tutorials!!!
Can I please know what are changes we need to make if we want to run a steady simulation? i.e. using simpleFoam solver
Thank you so much!
AMI only works with transient solvers
@@OpenFOAMJozsefNagy Sir, i had the same question.. Is it impossible to run a steady state simulation for fan/pump kind of problems in openfoam? Like mrf approach?
Great and very helpful tutorial! @József Nagy is the AMI a hollow or a plain cylinder?
I downloaded the geometry and tried to have a look on the AMI stl file as a part file in Creo Parametrics, i had problems but the AMI seems solid?
STLs are triangulated surfaces.
Thank you sir! This is really helpful!
Hi! This video is awesome thanks.
If I have a case where the rotation of the mesh is determined by the surface forces acting in my geometry (i.e a fluid-structure case). Does OpenFOAM has a case/code where you can simulate that?
Hello ! Im new in openfoam so the question may be a bit silly... when doing the surfaceFeatureExtract, I get an error that says: keyword extractfromsurfaceCoeff is undefined in dictionary. How can I solve it ? Thank you in advance!
I see, you are most probably not useing v1812 or v1906 but rather v6 or v7. Try switching OF versions.
Hello József, thanks for all the work in putting this together ! I noticed when running this that my fan isn't actually rotating as I move forward in time. Does this suggest that I need to make changes to the boundary condition specifications? I am using v10 so I had to make some minor syntax changes specifically in the createPatch, DecomposePar and surfaceFeatures dict. Furthermore, I gather that the AMI condition for simulating rotation is being phased out, is this correct and should this case still run in v10?
Unfortunately the .org version is by design not compatible with any other versions, so you are on your own. I would suggest to switch to the .com version, which values backwards compatibility.
Sir what is the solver to be used in centrifugal pump with water in steady state? MRFsimpleFoam is missing in my solvers.
Hi jozsef!
I modified the geometry of this tutorial in blender (basically mirrored the fan and AMI). The snappyHexMesh was successful with one rotatingzone cellzone formed. Now I want to define two rotating mesh regions but my simulation crashes without any error after defining two rotating mesh regions using dynamicMultiMotionSolverFvMesh. I think the error lies in dynamic mesh. Is it because there is only one cellzone?
Any guidance would be appreciated. Thanks alot for these tutorials!
You need multiBodyMotion, check which version of OpenFOAM you have and go through the tutorials folder for a tutorial which uses multiple AMI-s and us e the syntax there.
Thank you! It's very clear. I have a question, though. Where did you set the AMI_slave patch? It seems like the geometry only has 1 surface for AMI patch called "AMI"
It is then split into two parts.
Is there a possibility of having laminar flow in rotating problems? What is the characteristic velocity in these cases, the rotational velocity (omega*R) ?
Yes it is possible. You have to change the setting in turbulenceProperties. The rotational speed will have to be slow. Depends also on the geometry.
Always excellent. Thank you very much :-)
Hello József, thanks a lot. My question is: can Rotating-mesh be used with any solver ( for example ChtMultiRegionFoam for steady or transient ).
No. not steady and the transient solver has to be able to read in dynamicMeshDict.
Hello József, I have few questions regarding cyclicAMI patch..
1) How does openfoam differentiate AMI1 & AMI2...?? Do I need to give that patch name in geometry file...???
2) In this case, you have used the hollow cylinder geometry as AMI.stl , the rotating zone should always be hollow or shell type...?? & does it must be closed body...???
A big love to you. Thank you.
Thanks a lot, József! I just found your tutorials, which is a huge help starting with OpenFOAM. Although having 0 experience with CFD, I find it very interesting (and even perhaps useful in my work). With that said, would it be possible for you to speak more about some of the parameters, which OpenFOAM users might want to change running their simulation cases? For example, what do certain constant/parameters mean (physical meaning), what could we expect, if we change them (it is very clear, what would happen with changing gravity sign, but less clear with other constants/parameters); e.g. what does nu in Newtonian stand for? Shall the value be changed? (just as example). Perhaps it would be possible, to add comments in the tutorial files, which holds all those constants and parameters, what is where, and what each of them do/and does it need to be changed in certain cases (if some OpenFOAM user has this done, could you please share such files, I believe it would be great help for those who just start)? Myself, I am interested in aerosol particle flow simulation. I would highly appreciate, if someone could share particle simulation related OpenFOAM tutorial files, which include explanations for constants and other parameters (e.g. physical meaning; which parameters/constants should be changed). This is perhaps a lot to ask, because everything depends on the case... But I thought to try anyways.
I thank you once again for such a beautiful material!
I try to do this in my basic and intermediate playlists.
Hello József, thank you for putting this video together. It was really helpful. Could you please point to which line in the dictionary file is actually creating two surface meshes, AMI and AMI_slave, from one geometry which is AMI.stl? Thank you.
it looked like it was at the createPatchDict around th-cam.com/video/qtN256WJ-5I/w-d-xo.html
Please use white BG console for TH-cam otherwise 1080dp resolution is needed to see anything on the screen. Thank you.
Thank you for the very insightful tutorial! I learned much about dynamic meshing and parameters to consider in simulating rotation. However, in running this tutorial, I encountered a problem with relVelocity wherein a FOAM FATAL IO ERROR is met when trying to wmake the function.
What is relVelocity?
@@OpenFOAMJozsefNagy It is a function included in the system folder of the most recent iteration of the tutorial case files. It wasn't discussed in the video nor was it mentioned in the openfoam .com tutorial.
@@OpenFOAMJozsefNagy Regardless, I just removed the function and the simulation seems to be running well. Just a heads up for those encountering the same problem.
While running surfaceFeatureExtract I get this error "keyword extractFromSurfaceCoeffs is undefined". I added that keyword and it ran successfully but I get this line saying "Feature line extraction is valid on closed manifold surfaces only".
Do you use the foundation version of OF?
@@OpenFOAMJozsefNagy I am using the developer version just the way you did it.
@@parasghumare5864 Hello, I use openFoam7 and I had the same problem as you.
You can try this:
in the ControlDict file, replace writeControl adjustable; by writeControl adjustableRunTime;
and in the file surfaceFeatureExtractDict, replace
door.stl
{
extractionMethod extractFromSurface;
includedAngle 150;
}
by this:
door.stl
{
extractionMethod extractFromSurface;
extractFromSurfaceCoeffs
{
includedAngle 150;
}
writeObj yes;
}
do the same for each.stl file
I haven't finished the tutorial yet, but by making these changes, I managed to generate the mesh and view it in paraview
@@eti1316 i have already finished the tutorial and some of the changes I had made are the ones you have suggested. I was just wondering what that warning line means?
@@eti1316 Thank you!
Great work... But is it necessary to use snappyhexamesh? For this purpose... I use ICEM CFD for meshing
If you have the license, go for it!
Respected Professor, Really useful tutorial. I had a doubt, If I am exporting the mesh from Ansys, how I can specify the movingWallVelocity/cyclicAMI type? Thank you
topoSet and createBaffles might work.
@@OpenFOAMJozsefNagy thank you...will try
Is ceiling part inside AMI zone treated as rotating object too, or its data are interpolated to behave static? I mean if i leave some wall mesh elements inside this zone does it act like movingWallVelocity against my flow?
No, if you set the velocity to 0 0 0, it should not have a relative velocity.
Firstly, thank you for your work. I have a question: Can I define two rotating mesh regions with different rotational speeds? If yes how would I define them in dynamicMeshDict. Could I simply write rotatingZone1 {solidBodyRotationFunction ....; origin ....; axis ...; omega ...;} and rotatingZone2 {........}?
Hello! I want to do the same but my simulation crashes without any error after defining two rotating mesh regions using dynamicMultiMotionSolverFvMesh. I think the error lies in dynamic mesh. Were you able to successfully simulate two dynamic mesh regions?
@@Bushra-no9ph Any luck?
Thank you for this tutorial!
I have some questions about this case:
Using ./Allrun with OpenFOAM 5.x does not provide a solution.
Is this because of the version of OpenFOAM?
When entering commands individually instead of using the batch files, the case meshes and converges, but the fan does not spin. What could be preventing the fan from spinning?
Thanks!
The tutorial is set up for v1912 and now v2026. You might have to modify things for the foundation version.
How many steps in this tutorial are different when using in openFoam v8? There's an error when I typing "surfaceFeatureExtract".
Some syntax is different. You have to check the snappy tutorials in v8 for the correct syntax.
@@OpenFOAMJozsefNagy Gotcha, thanks a lot.
Hi József,
why is it necessary to use the "movingWallVelocity" for the U field? Why is it not useful to apply the noSlip condition there or a fixed value of (0 0 0)? Since the fan and the cells within the AMI patch are rotating, I thought that a noSlip wall is enough. It seems that this is not the case.
With respect to the turbulent fields you used the same wall functions for the fan wall as for the other walls and no special moving wall function.
The explantion of "movingWallVelocity" in the documentation:
"Sets the velocity to the desired value for moving walls when employed in moving mesh cases"
is not very meaningful to me.
I would appreciate some further explanation.
Very interesting video. Thanks!
movingWallVelocity applies omega*r to the wall which is obviously needed if the wall moves
movingWallVelocity leads to a velocity of 2 * pi * Rotational speed * Radius at the cells of the patch. It is determined by (pp.faceCentres() - oldFc)/deltaT. Location of new patch cell center - old patch cell center divided by the time step size.
What's the criteria for determining the timestep? 0.0002 is very low for such small angular velocity, I think?
Dear sir, Could you please upload a tutorial on simulation of vertical axis wind turbines.?
Hello Sir. Is it possible to use this method for simulating periodic linear motion? (Such as valve inside a piston going up and down)
Yes
Nice work. Whats the major chances we have to do to make a simulation of a 2D fan rotation?
The empty boundaries.
@@OpenFOAMJozsefNagy If I put empty in the boundaries conditions of certain "walls", OF considers that the simulation its done in 2D? That "wall" should have any special name? or I could rename as front and back for example?
@@joaquimmonteiro2548 You can call it as you want. The type is important.
@@OpenFOAMJozsefNagy I've manage to adapt your case to my situation. After a while (0,26 seconds) the simulation crashs and gives the error exit 142. Do you know what it means? Thanks
@@joaquimmonteiro2548 Unfortunately, check the Co number. Maybe your mesh quality is poor at some location.
Hi professor, is it possible to run steady state simulation with rotating domain?
Thank you for this tutorial. I have a question for the geometry in blender, is the desk a cutout from the cubegeometry of the room?
No, an additional STL durface.
@@OpenFOAMJozsefNagy Oh, I didn't know that could be done. That would save a lot of time not having to 'subtract' all the extras inside an enclosure.
@@BobBeatski71 That is true.
@@OpenFOAMJozsefNagy Don't have OF setup at the moment.... Do we still need to have openings in the room floor for the surfaces of the table's feet ? (The surface of the table foot in contact with the surface of the room floor; this would create non-manifold instances, yes ?)
I could just download the files and look, couldn't I ?. [EDIT: Yeah, the table is a solid item and there are no opening in the room floor for the feet. Only opening in the room for the door and window. This would hugely simplify my Rhino work as previously I have been merging all items into a single, solid STL.]
I've been trying to adapt this template to run a quadcopter simulation (4 rotating AMI zones) with dynamicMultiMotionSolverFvMesh. I keep getting floating point errors :S
Hi JJ, I answered you on Patreon!
@@OpenFOAMJozsefNagy Cheers! I sent you a follow up reply. I found a workaround :)
Hi Jozsef, i wanted to give the tutorial a try but i can't seems to download the case files with the link provided. I got page not found error when i click on the link to the files.
Yes, currently the source of OpenFOAM is down. Hopefully, it will be up again soon.
Great work. I am thinking of using OF for high speed turbomachinery applications like gas turbine turbofans .
Do we have any such tutorial I can refer to
thank you
Unfortunately not.
After a longer break from simulation I started this tutorial again, what could be the reason that when I create folders in windows there are shown in ubuntu but I can't open them? Do you have any advise?Thank you.
Permission problems maybe?
how should I prepare the geometry for the flow domain? Should it be a cylinder or a thin-walled pipe with thin caps as inlet and outlet????
I am not sure, whether I understood your questions correctly, but you do not have to add a thin wall.
@@OpenFOAMJozsefNagy Thank you for your reply.I checked your geometry, the AMI is just a shell, is that the right way? Can the AMI just be a solid cylinder? Also, it seems that the inlet, outlet, and the room are just faces or thin layers.
@@estaykylyshbek8347 Yes this is correct.
Why to use movingWallVelocity BC for fan and not noSlip when AMI is already there? Is rotatingWallVelocity a BC too?
You need it because the simulation is run in the external non moving reference frame and you have to account for the relative motion of the mesh.
@@OpenFOAMJozsefNagy But if that's the case then why did you put the value as uniform 0?
Why didn't you assign a rotatingWallVelocity BC and specify the rotation characteristics?
Bit confused 😅
@@parasghumare5502 uniform 0 ist a starting value and is overwritten by the code. The rotation characteristics are not specified in the BC but in the dictionary in constant.
Is it possible to simulate half domain (a symmetric one) with a sliding mesh in openfoam? Then use symmetry conditions.... would that work?
I actually tried it some time ago and it crashed
Cheers!
I am not sure. I never tried, but I do not thinks so as the rotating mash does turn with the symmetry plane.
Hi, can we use this tutorial to modify it and apply MRF technique instead of AMI? Thank you so much!
Sure. You need a cellZone and a MRFProperites file
@@OpenFOAMJozsefNagy Thank you so much for your reply! Sorry for getting back so late. May i also check if this method applies only for transient or does it apply for steady state simulation as well? Thanks again!!
@@jegga007 It works theoretically also for steady state,
Hi Joszef, I'm fairly new to openfoam and I am getting this error when running the mpirun command: environment variable MPI_BUFFER_SIZE not defined. How can I solve this issue? Thanks in advance
If the simulation is running, you don't have to worry about it. Or does it crash?
@@OpenFOAMJozsefNagy it crashes
@@rokasbytautas5074 MPI_BUFFER_SIZE=2000000000 Does this help?
@@OpenFOAMJozsefNagy Hi sorry it still doesn't work. Where exactly does this need to be defined?
@@rokasbytautas5074 In the command line before starting the simulation.
Great tutorial, very useful! I noticed you indicated an angular velocity as the driving factor, but is it possible to specify the air as the driving factor? If so, how? To give an example of what I mean, right now you have a motor turning the ceiling fan at a constant velocity, but I'm interested in simulating a wind turbine spinning up from 0 omega based on the windspeed acting on the blades.
Best regards!
Puh, a time dependent angular momentum? I am not sure whether this is implemented :/ You can try increasing it manually.
@@OpenFOAMJozsefNagy More like a flow/pressure driven angular momentum.
@@mishaparem I see, you need the 6dof model for that.
how did you build your geometry? What is the thickness of AMI wall, inlet and outlet.
No thickness required. I used blender to construct it, but and CAD tool with a good STL export will work.
Thank you very much sir! I have a big problem about what kinds of boundary type should we choose, for example in this tutorial. This confused me and my friends.
At which boundary?
Hello, I'm trying to run the surfaceFeatureExtract command, but I get a message that says this:
surfaceFeatureExtract: symbol lookup error: surfaceFeatureExtract: undefined symbol: _ZN4Foam9UOPstream5writeERKNS_5tokenE
and I cannot pass from here :( I've tried downloading the whole source code and running it from there, bu I have the same message, I wonder if you could help me please.
This is weird. Do you get the same error with a different version of OF?
I had the same problem at first. It went away after a complete delete and reinstallation of OpenFOAM. But in the second run i got the error that controlDict, using the surfaceFeatureExtract function, cannot be found. Looks like this:
FOAM FATAL ERROR :
Could not find mandatory etc entry (mode=ugo)
'controlDict'
hello
thank you for your tutorials
i have make all the instruction in this video but in the end when i run the simulation the fan doesn't rotate ; i didn't understand what i should change.
thank you
What did you change?
@@OpenFOAMJozsefNagythe only thing that i change is in bondary wall to patch
@@oumaimaboualam5803 What is the reason for that?
@@OpenFOAMJozsefNagyexactly like you have done for the door and the outlet
but generally i have all done like you but the problem is that the fan doesn't rotate in the simulation
thank you for your help
@@oumaimaboualam5803 Are you using the correct openfoam version v1912?
Dear Sir,
The link of the case file doesn't working. Where else can I find the case?
I noticed as well, that the link is broken. I contacted the responsible person at OpenCFD, hopefully the files will be accessible soon.
@@OpenFOAMJozsefNagy Dear Sir, I have problem with local porosity distribution along length and width, the available solver only handle the constant porosity. Can You please help me to sort it out?
Thanks in Advance.
Hi Jozsef, i tired to make this tutorial which is really good to learn something. I had a problem when i run the simulation, this is look like due to relVelocity/ Using dynamicCode for functionObject relVelocity at line 13 in "/home/aokaya/OpenFOAM_files/rotatingFanInRoom/case/system/controlDict.functions.relVelocity".
Thanks For videos and helps.
Excellent work
How can I change this case to run a simulation for a horizontal axis wind turbine?
Change the STL files, the settings for meshing, the case setup and there you go ;)
@@OpenFOAMJozsefNagy My flow domain is a giant cylinder, should it be a solid body or just a shell structure like your room stl.
@@OpenFOAMJozsefNagy Thank you so much for your reply.
@@estaykylyshbek8347 It doesn't have to be 100% water tight as long as the gaps are smaller than the final mesh resolution.
@@OpenFOAMJozsefNagy Thank you for the answer but I am still a bit confused. May I send you an email and include my STL files?
Hello Józef,
I have a one question. I can't start my simulation. I have this ERROR during last step in tutorial.
[0] --> FOAM FATAL IO ERROR:
[0] Wrong token type - expected string, found on line 20: word 'fvMotionSolvers'
[0]
[0] file: /mnt/c/Users/monki/Documents/rotatingFanInRoom/case/constant/dynamicMeshDict.motionSolverLibs at line 20.
[0]
[0] From function Foam::Istream& Foam::operator>>(Foam::Istream&, Foam::fileName&)
[0] in file primitives/strings/fileName/fileNameIO.C at line 60.
[1] --> FOAM FATAL IO ERROR:
[1] Wrong token type - expected string, found on line 0: word 'fvMotionSolvers'
[1]
[1] file: IOstream.motionSolverLibs at line 0.
[1]
[1] From function Foam::Istream& Foam::operator>>(Foam::Istream&, Foam::fileName&)
[1] in file primitives/strings/fileName/fileNameIO.C at line 60.[2]
I have OPv1906 installed from your tutorial on Ubuntu in Windows 10. How can I solve it ? Thank you in advance!
Best regards!
Hi I have the same error, how did you solve it?
For people who as me had the same error, it should be solve with "fvMotionSolvers" in the motionSolverLibs of the dynamicMeshDict of system folder, this is just to indicate that is a string.
I have a question for openfoam, which can solve scroll pump project
Maybe an overset solver would work.
For the tutorial files working with openfoam v8 search in git hub for josoHub/rotatingFanInRoomOFv8. Please read the file README for instructions. And thanks for the tutorial.
Thank you!
this comment should be pinned up, thanks :v
Hi Jozsef, I have tried to modify this tutorial by replacing the geometry. But I cannot run the simulation, could you please check my geometry? I will send it to your email if you have time to take a look at them.
I don't say any stl file in the constant directory.
Check to Allrun script, OpenCFD moved the STL files to a different location. If you check the tutorial folder of your v2012 installtion the files are still there.
Great tutorial. Sir I have a question here. How big we should define this rotating domain size. For propeller or fan, yes I agree the rotating domain shape is cylinder. But I'm not clear about the distance from the propeller or fan to the faces of the cylinder (read : cylinder radius and length). It would be nice if somebody could enlighten me. Sorry for the trouble and have a nice day to you all ;)
It should be as close to the fan as possibly, but the refinement of the fan/blade should not influence the refinement on the AMI. At least this is my experience.
@@OpenFOAMJozsefNagy thanks alot for the reply Sir. Your experience is valuable to me since this is what I lack of as relatively new explorer in dynamic mesh user. So, based on your experience, this is what I get : suppose my AMI refinement level is less than the refinement in propeller surface. While I define AMI surface to get as close as possible to the propeller, I should be careful to define the distance from the AMI to the propeller so that pre-set AMI surface refinement level not affected by colateral or induced refinement from more refined propeller surface? Could you elaborate why this consideration is important.
Just for the info, right now I'm predicting thrust of 2 meters of diameter of fixed pitch propeller for the aircraft rotating at 2200 rpm by using CFD. I consider using compressible solver and I have tried CFD simulation in openfoam using MRF approach (steady) and sliding/rotating mesh or AMI (transient).
@@dickymulyoaditama6284 The interpolation between coarse and fine cells could be problematic. That's all.
Sir, can you provide zip file on Google drive.
There is an error called 404 came while trying to download it.
It will be helpful if you provide us.
Thank you for noticing. They changed the address to it. I updated it in the description. develop.openfoam.com/Development/openfoam/tree/develop/tutorials/incompressible/pimpleFoam/RAS/rotatingFanInRoom
Please sir what is the relevance of this simulation to a civil engineer
To be able to deduce your own case.
Hi Jozsef, dear community
thanks for your tutorial it was very helpful. With your video and the entry on the OpenFoam website i was able to finish the tutorial. I tried to change the geometry and it worked until the last command. When i try to run mpirun -np 4 pimpleFoam -parallel > log.pimpleFoam & the following problem report appears.
[0] --> FOAM FATAL IO ERROR: (openfoam-2112)
[0] Cannot find patchField entry for procBoundary0to1
[0]
[0] file: processor0/0/p.boundaryField at line 25 to 62.
[0]
[0] From void Foam::GeometricField::Boundary::readField(const Foam::DimensionedField&, const Foam::dictionary&) [with Type = double; PatchField = Foam::fvPatchField; GeoMesh = Foam::volMesh]
[0] in file /usr/src/packages/BUILD/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 172.
[0]
FOAM parallel run exiting
[0]
in file /usr/src/packages/BUILD/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 172.
Any help would be appreciated.
With kind regards
Benedikt Bihlmayer
Possibly there was an issue during decomposePar already?
@@OpenFOAMJozsefNagy Thank you for your fast answer. I will Check it.
@@OpenFOAMJozsefNagy Hi Jozsef,
I tried to run the simulation again and edited the code. You were right that during decomposePar was the following issue
--> FOAM FATAL IO ERROR: (openfoam-2112)
Cannot find patchField entry for allBoundary
file: 0/k.boundaryField at line 25 to 62.
From void Foam::GeometricField::Boundary::readField(const Foam::DimensionedField&, const Foam::dictionary&) [with Type = double; PatchField = Foam::fvPatchField; GeoMesh = Foam::volMesh]
in file /usr/src/packages/BUILD/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 172.
It would be great if you can tell me what i am doing wrong. Thanks for your help i do appreciate it a lot.
With kind regards
Benedikt Bihlmayer
@@benediktbihlmayer9004 Your original BC from blockMesh is not deleted during snappy. Take a look at your mesh. Looks like you don't cut away your outside for some reason. Not water tight STLs?
@@OpenFOAMJozsefNagy How can i check, if the STLs are water tight? I thought by running the command checkMesh i see if there is a problem but checkMesh returns that everything is ok.
Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
Number of regions: 1 (OK).
Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
allBoundary 14350 14352 ok (closed singly connected)
Checking faceZone topology for multiply connected surfaces...
No faceZones found.
Checking basic cellZone addressing...
No cellZones found.
Checking geometry...
Overall domain bounding box (-277 -47 -97) (1 47 47)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (-1.330152e-17 1.824875e-15 -1.336859e-15) OK.
Max cell openness = 1.734963e-16 OK.
Max aspect ratio = 2.808359 OK.
Minimum face area = 7.285986. Maximum face area = 20.52812. Face area magnitudes OK.
Min volume = 34.97463. Max volume = 35.08443. Total volume = 3756917. Cell volumes OK.
Mesh non-orthogonality Max: 0.3553395 average: 0.1683
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 0.006983165 OK.
Coupled point location match (average 0) OK.
Mesh OK.
Do you know any other options to take a closer look at the mesh?
With kind regards
Benedikt Bihlmayer
HiJozsef, when I run surfaceFeatureExtract, it says symbol error. And I can only find surfaceFeature and surfaceFeatureConvert in the utilities directory. Is it because of the difference due to the latest version of openfoam?
You may use the foundation version instead of the OpenCFD version. There are some syntax differences there.
Dear sir, Could you please upload a tutorial on simulation of vertical axis wind turbines.?