CFD DEM Tutorial - coupling OpenFoam and Liggghts
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- Опубликовано: 15 апр 2020
- This DEM CFD tutorial of CFDEM should help to understand what is necessary to use the opensource coupling of openFoam and Liggghts.
The files can be downloaded from www.engineerdo.com. 
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Interesting video. Thanks for sharing. Tobi
Thanks Tobi!
You are welcomed. I do similar things but not as nice as you do. I love that DEM stuff. Never used it and Liggghts is still a software I never used.
@@HolzmannCFD Same for me with openFoam until I got enough inspiration from you and your channel a couple years ago.
@@engineerdo6568 Very humble conversation, nice. Holzmann CFD got a new subscriber.
Thank you for the good tutorial. In combination with the example files it was pretty easy to set up a similar simulation.
It's one one of its kind tutorial, I like it.
Cheers mate!
It was very interesting. Waiting for more :)
Just re-watched this video as I want to do some proper CFD-DEM coupling. It's a great tutorial right up until the coupling phase which is the last and most important bit. It's then rushed through in 30 seconds flat and actually makes it very difficult to follow if you want to transfer it to a new case which is what I'm wanting to do
Well maybe a new video will go more in the details there. Sometimes not easy to put everything in a video of less than 8 hours...
very good work and tutorial with details.
Hey Kevin,
Thank you! Cheers!
it is so useful thanks for sharing
Thanks for your comment. I really appreciate
Good work, my friend!
Hey Aussie, Thank you! Cheers!
great this is really helpful....thanks man....
Hey Rana, thanks for your feedback. We appreciate :)
@@engineerdo6568 my pleasure
Wow! Finally a good tutorial. I am new to this concept, though I am so curious to learn DEM. Can you tell me about some sources to learn DEM? So, I can use it in my research field. I am an undergrad in Civil Engg.
Thanks Muhammad! You are welcome to cite me bit.ly/3db6pUh ;-). If you have a look on ResearchGate you will find a lot of publications from researchers all over the world which you can cite.
Finding these videos really helpful for setting up my research. Are there any free alternatives to Helyx for Windows which I could use?
Hey Daniel, thanks for your question. there are a few possibilities for Linux but I'm not sure if they will work under windows. Maybe you can find a open-source front-end and convert it to compile it under windows.
👏👏👏👏 thanks for sharing
You are so welcome, Javier.
Thanks for sharing this video. What is the software for creating the initial configuration?
LIGGGHTS for the particles and openFoam for the fluid
Thanks for the tutorial. I wonder how LIGGGHTS can be used for DEM_SPH coupling models.
Hey peyman, please tell me, when you find out
At first Thank you for sharing!! I have a question Why one would use different timesteps for DEM(liggghts) and CFM(OF) in a coupled simulation?
The CFD mesh is considered to be large in comparison to the dem particles. So usually the timestep required for the CFD simulation can be bigger than the timestep in the DEM simulation. Usually it's around factor 10. If it in the region of factor 1 or 2 the coupling will be very slow because it was not designed to have an equal time step
this is really helpful ! thanks a lot, I see a file called state.pvsm in the DEM folder, what is the use of this file?
Hey Abdelrahman, that is a input file for paraview to standardise the postprocessing.
hey, what's up, how are you doing, hey I have a problem in the last step in helyx, give it run, this message appears, "Process exited with an error: 1 (Exit value: 1) do you have an idea how to solve it, thanks in advance
Hello, long time with a new video hope all is well with you. can you please tell For this tutorial what version of ligggths, OF and helyx did you use?
OF 5.x coupled to liggghts 3.8.0 and Helyx-OS 2.4.0
You guys are doing awesome work. Could you share what workstations you are using? I am a phd student with funding to purchase a workstation. My brief research suggests that after 32 cores, the computational speed is nonlinear... What do you think? Again awesome work.
Hey Sung Ryoo, it depends on the case you want so simulate. Not every case will run in parallel very well. If you have to choose between speed and number of cores go with the cores. 32 cores are definitely enough for a single simulation. However, if you have a bunch of simulation you wish to do in parallel then the more cores can accelerate the results. We are using computers between 8 and 24 cores. If you are writing data very often and your simulation also contains more than 1e6 particles a fast HDD with 2 TB is also a good investment.
@@engineerdo6568Ah I see. Thanks! Also, do you plan on doing a simpler coupled tutorial later on? Maybe a cylinder thats filled with particles and fluid running through it? I am having a hard time understanding the openfoam side of things. I set up my LIGGGHTs script and it works fine but I am not clear on the cfd side with questions such as "Does the blockmesh need to match the domain I created in liggghts?" etc. The tutorials given by CFDEM isn't clear to me (and most people according to the forum questions haha).
Yes indeed! We are planning on a fluidised bed in the near future.
hi i have a problem while starting the simulation and it is related to the number of processors in files. how to reduce number of processors from 12 to 4? i have tried but still error
thanks
thank you for this tutorials.
May you assist me with guides or resources of CFD DEM coupling.
Thanks RetRet, beside this video and the official documentation there is very little available. We are working on a step by step guide on pure website.
Hi EngineerDO, can you please share the version of Helyx, OpenFOAM, LIGGGHTS, CFDEM, and Paraview you have used in this simulation? I have this version compatibility issue, and thus I am not able to replicate the simulation. Thanks. Regards.
I'm using liggghts 3.8.0 with openFoam 4.1. Newest coupling. Paraview 5.0.0
It would be awsome if u could mk a video on how to set up ligggths on windows and thanks for the hard work
Hey pain, yeah it´s noted. First will come a tutorial for installing on linux, but afterwards we also plan a tutorial for windows installation :)
Very interesting! I need to couple Liggghts other Ansys fluent. How we can do this?Thank you in advance
Hey Mohamed, that's no easy. Is it really necessary to use Ansys. You can export your case from Ansys to openFoam and solve it there. That should be a year or two faster than creating a coupling and validating it.
Hello I hope you can answer this question! How did you convert timestep into time (seconds)? I am not sure if this is a dumb question or not.
Hey ENCE, you can use a Annotate Time Filter in Paraview on VTKs or program a python filter which takes the timestep and multiplies it with your timestep.
@@engineerdo6568 I see. Learning about CFDEM has been very fun and challenging. You guys are making it possible for students like me to get comfortable. Thank you very much!
@@engineerdo6568 Is it an accurate representation to scale it to the deltaT? Does it actually represent a real world scenario?
If it does, that is awesome since it's so easy.
Hi ! Congratz. I was wondering if you can explain how you get the coupling of openFoam and Liggghts. I mean, this opensource is CFDEM coupling??? and How you got to install this opensource??? I tried to install this (following the guide in the official web) but i couldnt to run the examples. I believe that i made a mistake with openfoam installation or/and on step for the coupling. Can you guide me a few??? I would really like if you can a tutorial about this. Thanks !!
Same here I had a lots of problems trying to install cfd-dem and still no results.I would appreciate a lot a tutorial of the coupling of CFDEM
Hey Eduardo & David,
we have it on our list to do a video tutorial about the installation of openfoam and liggghts for coupled simulations.
Cheers, EngineerDo
I also had the same problem. It's problematic to compile openfoam 5.x or earlier releases(the official supported versions by CFDEM-Coupling) in ubuntu 20.04
Can you suggest some tutorial and guide to so that i could learn more about hopper design using open source software's
Hey Nithin, thanks for the comment. We will upload a video focusing on hopper design comparing mass flow and funnel flow soon. EngineerDo
Im trying to follow this tutorial, but I cant find "Allrun.sh" file. I get (copy) one of the tutorial examples, but it doesnt seem to work properly. Can you share that file?
You can run the simulation by executing ./runMe.sh
could you please send me a link I can download dem software
how about showing one tutorial of the resolved one? thanks
Hey Wang, thanks for your input. What do you mean with resolved?
Hi EngineerDo, can you please elaborate the part between 15:00 to 15:30, I am not able to follow the steps. Also, I can see a file at 15:00 named 'runME.sh' but this file is missing in the downloaded folder (I downloaded the whole case from the website, www.engineerdo.com/2020/06/24/cfd-dem-tutorial-vacuum-excavator/). Thank you, best wishes!
Hey Vimod, you are right. I uploaded a new version where you will have the runMe.sh file. Please execute this file using "./runMe.sh" in a shell.
@@engineerdo6568 Hello, Can you point me to where the file with the runMe.sh file is. I have downloaded the zip files off the webpage and and it still appears to not have the runMe.sh files in it. Also what is changing in the CFD files when we replace them with the ones you have supplied.
@Engineer Do can you tell how do i run the last steps you said to run the script how do i run that can you give me the code for the same...
Please open a shell/terminal in the folder and run the simulation with ./run.sh
@@engineerdo6568 It is giving a error" cp: cannot stat 'S_con.stl': No such file or directory
./runMe.sh: line 19: cd: $casePath: No such file or directory
/home/pakhi/COUPLING/WorkingCase/parCFDDEMrun.sh: line 4: /home/vc-a/dem/.bashrc: No such file or directory
/home/pakhi/COUPLING/WorkingCase/parCFDDEMrun.sh: line 7: /lagrangian/cfdemParticle/etc/functions.sh: No such file or directory
/home/pakhi/COUPLING/WorkingCase/parCFDDEMrun.sh: line 26: parCFDDEMrun: command not found"
It seems, that the coupling is not installed correctly
How can we generate a list for element_exculsion-list?
Hey Yassin,
to use exclusion list you have to generate it by pre run the simulation for a few steps. There you write the exclusion list. Than you can use this list in your real simulation.
Example:
First Presimulation:
fix cad1 all mesh/surface file CAD/fixed1.stl type 1 element_exclusion_list write blacklist_top.txt
fix wall all wall/gran model hertz tangential history cohesion off rolling_friction epsd2 mesh n_meshes 1 meshes cad1
run 1
Second (real) Simulation:
fix cad1 all mesh/surface file CAD/fixed1.stl type 1 element_exclusion_list read blacklist_top.txt
Cheers
@@engineerdo6568 Thanks a lot
1:42 Blender
4:17 Helyx-OS
Ubuntu 20.04?!
Hey Marcelo, it will work with ubuntu 20.04. I'm currently working on a installation tutorial. At first for OpenFoam and Liggghts themself.
@@engineerdo6568 Where can I find the Ligggths installation tutorial? Can you show me?
@@McHumaty sorry, we are still working on it....
hi! i found this tutorial ruclips.net/video/42njAhFamjU/видео.html hope its useful!