How to run parallel simulations in OpenFOAM® - Part 1

[@x.y.8707]

This is a very useful tutorial. I have a question when I try to repeat the tutorial. I am using openfoam 8 at a window 10 based ubuntu. So, after I run setFields, the fielddata created by this command is not readable. For example, when I using nano command to open the 'alpha.water' file, it is '..... 12800 ( ð? ð? ð? ð? ........... )' . However, I was expecting the unreadable data should be values between 0 an 1. Another wierd thing is that the case is running OK and the flowfield results in paraview is similar to your tutorial although the field data is unreadable using nano command. Could you help with this?

[@OpenFOAMJozsefNagy]

Do you use binary format?

[@x.y.8707]

@@OpenFOAMJozsefNagy I just checked the controDict file, the writeFormat is 'binary'. So, this is the reaon. Thanks for your suggestions. It helps.

[@xiaoxiaoxu-jv4nn]

@@x.y.8707 I met the same problem, how should I solve it?

[@JZ1917]

Another very nice tutorial!

[@sumitzanje5207]

Can you make a video to run openfoam case file parallel using Slurm (HPC)?

[@fizzybubblyify]

Did you have any success with this?

[@PratyushVihar]

Hello Sir, your tutorial is really helpful. I am able to run my cases on multiple processers using decomposeParDict utility. However, I have to run my simulation on cluster. Earlier, I was using ANSYS for CFD analyses. For ANSYS, there is a single script to run any simulation on other nodes other than master node just by changing the case and solver. I am searching for same type of script for OpenFOAM too. Kindly, guide me for the same. Thanks in Advance !!

[@OpenFOAMJozsefNagy]

This is highly dependent on the cluster. You have to talk to your admins.

[@arungomathi1224]

Hii sir i am trying to implement custom model it works well with single core but for parallel it gives a warning that it couldn't find the .so file can you please give me some help

[@LisAmigo]

Hi, have you solved your problem? I have a self-written boundary condition, and the decomposePar doesn’t conserve this boundary when calculating. So then I cannot reconstruct because it says I haven’t specified a boundary

[@cdvs100]

Hi József. I recently install to my laptop Ubunto 20 and after I run setFields, it run ok so far, and I tried to see the alpha.water from nano, to see the change, but it didn't response so I couldn't see the list of numbers, it's not possible to see the list, the weird is that I executed the solver and it run ok but I couldn't see this file, and I tried to read the file on windows and this can be open but in the list appear null value. It never happened to me on windows, do you know why? by the way I'm using OpenFoam foundation 7

[@OpenFOAMJozsefNagy]

Uncheck maybe the skip zero time checkbox. A video on this is coming out tomorrow.

[@TheKeksmonster12]

Taken from: OpenFOAM® Basic Training by the TU Wien
If the above output is not displayed, but a stream of NULL characters, your text
editor is probably printing binary. To fix this, open system/controlDict, and change
the writeFormat field from binary to ascii and rerun the previous command.
Fixed it for me (:

[@parasghumare5864]

OpenFOAM v6:
My thermophysicalProperties.water file reads:
thermoType
{
type heRhoThermo;
mixture pureMixture;
properties liquid;
energy sensibleInternalEnergy;
}
mixture
{
H2O;
}
and the part which resembles your file has been commented out signifying it's obsolete. However, I tried using the commented part instead (as is your case) and it gives me error saying something like "thermophysicalproperties.water file read but found this instead of that". Why this error? I think both should work.

[@OpenFOAMJozsefNagy]

They changed it and split up the properties since 2.3.0. Just take a look at the thermophysicalProperties.water file.

[@parasghumare5864]

@@OpenFOAMJozsefNagy So writing H2O is enough? Does OpenFOAM recognize it without mentioning the details? My doubt is that the detailed part should work too.

[@OpenFOAMJozsefNagy]

@@parasghumare5864 As long as the simulation works this way you should be good.

[@mateuscouto5573]

Can I run snappyhexmesh in paralel?

[@OpenFOAMJozsefNagy]

Yes, the command for reconstruction is reconstructParMesh!

[@MrMangkokoo]

hello doc, how can i utilize my GPU for computing the case? thank you very much.

[@OpenFOAMJozsefNagy]

No, unfortunately not out-of-the-box.

[@SharperthanA]

You can use GPGPU or RapidCFD which are OpenFOAM based

[@MrMangkokoo]

@@SharperthanA do you need to compile yourself? Have you ever tried?

[@MarcoGuevaraLuna]

Thanks doc.

[@AdityaKadamMechanical]

Thank you Sir :)

[@thecoolcrasher]

great :)

[@lila9306]

I really like your videos, thanks. But You can't make it any shorter than 30 minutes is too much!

[@OpenFOAMJozsefNagy]

Take a break at 15 min ;)